This article was updated on 13th January, 2022.
The evolution of mobile network infrastructure and protocols go a long way back. Every new generation of mobile networks has offered new opportunities for end-users.
Today, we still have the traditional cellular networks in use - 2G, 3G, 4G and the addition of 5G. Still, new technologies like NB-IoT and LTE-M are being deployed.
When it comes to picking the right network type for your cellular-based IoT project, decision-making might get tricky.
When it comes to M2M and IoT devices, all the networks mentioned above are technically accessible, and cellular modems are available. However, there are many things to consider when choosing the proper cellular network modem for your next project.
First you need to think of the bigger picture and decide, in which regions your devices will be used. Will there be any roaming restrictions in the area to consider? Or if there even is a full coverage of 2G / 3G / 4G / 5G or NB-IoT / LTE-M in that region.There are several open-source options (along with telecom coverage maps) for finding out the coverage of mentioned network types in different regions. One example would be the OpenSignal application, which has crowdsourced coverage maps.
2G (short for second-generation cellular network) was first launched on the GSM standard in 1991. The technology enabled networks to provide novel services such as text and picture messages and MMS (multimedia messages).
With General Packet Radio Service (GPRS), 2G offers a theoretical maximum transfer speed of 40 Kbit/s. With Enhanced Data Rates for GSM Evolution (EDGE), the theoretical maximum transfer speed is up to 384 Kbit/s.
Despite being a legacy network, quite a few industries make good use of 2G. We're talking industries like logistics and supply chain, which usually involve devices that work in less populated areas. That could be remote loading docks where shipment is being handled, or remote locations in asset tracking.
2G is still a great option in those cases because, despite their increased speeds and capacities, the new cellular networks have come at a cost. The range of coverage has decreased, and the networks rely on more widespread physical installation sites, such as masts. They, therefore, are only concentrated around the larger cities in many countries. Also, 2G cellular modules are cheap, often being a reason why IoT device manufacturers are choosing to use this technology over the others.
Later 3G releases - 3.5G and 3.75G - provide mobile broadband access of Mbit/s. This ensures that the network can be applied to wireless voice telephony, Internet access through mobile and fixed wireless networks, video calls and even mobile TV technologies.
3G might be helpful in the healthcare industry, where patient tracking and monitoring doesn't need the bells and whistles of 4G and 5G. While upgrading to these newer cellular network technologies won't be difficult, it will create additional costs for both the healthcare providers and the patients.
That being said, 2G and 3G networks are subject to being shut down in the coming years. Which means that IoT devices using such network modems might end up disconnected.
In most cases, countries have picked either 2G or 3G to be shut down, not both. The procedure usually takes about 1-2 years, requiring careful examination and support by the local mobile operators.
Region-wise, Europe is considering shutting down 3G before 2G (e.g., Telenor in Norway). In contrast, telecoms in the USA are doing the opposite - shutting down 2G networks. However, Australia's telecoms will probably start shutting down both 2G and 3G quite soon.
A complete overview of 2G and 3G sunsets with dates can be found in our blog.
4G is a loose term for the fourth generation of cellular communications. It offers data transmission speeds about 10 times faster than 3G. Each generation of wireless cellular technology has increased bandwidth speeds and network capacity. 4G users get speeds of up to 100 Mbit/s, while 3G only promised a peak speed of 14 Mbit/s.
4G coverage is currently considered the best cellular network around the world. Operators have been launching 4G for many years, and it's not being shut down anytime soon.
While the coverage is good, 4G is not the best option for many IoT devices because of higher module cost, high power consumption and often, there is no need for high-speed data connections.
5G networks are cellular networks, in which the service area is divided into small geographical areas called “cells”. 5G is a huge step forward from 4G and its new developments (4.5G, 4.75G). The main advantage of the new networks is that they have greater bandwidth, therefore higher download speeds up to 10 Gbit/s.
The 5G network will be a good option for IoT devices and vehicles which use tens of gigabytes of data per month or need to be connected to mobile networks in real-time and 24/7.
The problem we are facing today in the IoT field is that mobile networks are not optimized for a huge amount of devices in a small area (all but 5G).
A considerable amount of IoT deployments use a minimal amount of data per month. For example, something between 10KB and 1MB. The telecom world is moving towards alternative network solutions - NB-IoT and LTE-M.
To find out more about these technologies and which one is suitable for your IoT project, read our Definitive Guide to LPWAN - NB-IoT vs LTE-M Comparison blog post.