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. As of today, we still have the traditional cellular networks in use - 2G, 3G, 4G and the addition of 5G but also new technologies like NB-IoT and LTE-M are being deployed.
When it comes to M2M and IoT devices, all the above-mentioned network types are technically available and modems are accessible. However, there are many things to consider when choosing the proper cellular network modem for your next project.
The first question to ask is: in which regions your devices will be used? Is there a full coverage of 2G / 3G / 4G or NB-IoT / LTE-M there?
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.
4G coverage is currently the best 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, for many IoT devices, 4G is not the best option because of higher module cost, high power consumption and often, there simply is no need for high-speed data connections.
2G and 3G networks, on the other hand, are subject to being shut down in the coming years, meaning that IoT devices using such network modems might end up disconnected. In most cases, countries and regions have picked either 2G or 3G to be shut down, not both of them. The procedure itself 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) whereas telecoms in the USA are doing the opposite - shutting down only 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 can be found in our blog.
In general, one needs to verify the network frequency bands which differ by country, and the device engineer must make sure that more prominent regions have similar frequency bands and work with specific modems.
Every country or region has its specific bandwidths available for all different network types. For example, in 2G / 3G and 4G frequencies in Germany:
|E-Plus||900, 1800 MHz||2100 MHz||1800 MHz|
|O2||1800 MHz||2100 MHz||800 MHz|
|T-Mobile||900, 1800 MHz||2100 MHz||800, 1800, 2600 MHz|
|Vodafone||900, 1800 MHz||2100 MHz||800, 2600 MHz|
Today many cellular modules already support multiple bands, but to be sure you will need to check the specification of the cellular module.
In summary, when planning to launch your next cellular-based IoT device or application, you will need to take into account the coverage of different network types, supported frequency bands, and fallback options from disabled networks.
The problem we are facing today in the IoT field is that mobile networks are not precisely optimized for a huge amount of devices in a small area. There are a considerable number of devices that use a minimal amount of data per month, for example, 10KB or 1MB. For such devices and cases, the telecom world is moving towards alternative network solutions - NB-IoT and LTE-M.
For M2M/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 5G network is being designed. 5G is a huge step forward from 4G and its new developments (4.5G, 4.75G).