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What is TETRA and how does this communications network for emergencies work?

Nowadays TETRA continues to be the network used by most critical communication equipment. As for the future, as we will see later, 5G has already been tested, although there is still a long way to go. 5G coverage in many large cities is a reality, but there is still a lot of work to be done.

How the TETRA network works

The ETSI, whose acronyms translated into Spanish mean European Telecommunication Standards Institute In the period of the 90s, the development of an open standard for critical communications was proposed as a goal to replace analog radios. Thus, with this objective in Europe, TETRA was created, which ended up ousting Project 25, another radio communications standard used in the United States and Canada.

Currently TETRA operates in more than 100 countries around the world. The answer to why it is present in so many countries is easy to understand. TETRA, due to the advantages it offers us compared to other existing critical network infrastructures, has led administrations and private organizations to opt for it.

One of the reasons that helped them win this fight was that most countries in the world have a band reserved for critical communications which is usually around 380-400 MHz as can be seen in the table that we put in the first section. In addition, this offers another additional advantage, as it is using such a low frequency, it allows to achieve greater coverage for each of the installed antennas. The same can also be applied to 5G when the 700 MHz are used against higher frequency bands.

Also another very important advantage is that We do not have an absolute dependence on the network to be able to communicate with TETRA terminals. Thus, in emergency events such as natural disasters, communication infrastructures such as mobile networks can be damaged and fall. The danger is that it can take days or even weeks for them to work well again.

On the other hand, with TETRA point-to-point communication is possible without the need for a standing network. It should be noted that it will not be with the same scope, but at least we will have communication between users in moments that can be critical.

The TETRA communication equipment that we use to have the most instantaneous communication and almost in real time would be:

  • Walkie-talkie radios.
  • Fixed terminals.
  • Some smartphones

Some incorporate a push-to-talk button that puts us almost immediately in communication with the rest of the teams that press the same button. This communication occurs in less than a second. In addition, transmissions will always be protected thanks to encryption end-to-end. This type of communication is generally used for voice, although it also allows data, although at a very low speed of about 10 Kbps. For this reason, the very low data transfer speed is considering taking a leap towards new technologies .

The technological transition to 4G and 5G

The most varied TETRA terminals have been presented at the CCW, Critical Communications World, in recent years. Here, we would have from the classic radios to the smartphones that combine TETRA with 4G. Thus, after more than 20 years of operation, TETRA continues to dominate and all forecasts indicate that it will not stop growing until at least 2023.

Proof of the good health of the business is Motorola Solutions which dominates this market globally. In the first quarter of 2021, it made a profit of almost $ 1.8 billion, 7% more than the previous year. However, after the news presented at the CCW, we see the critical communications sector in full technological transition. For example, we are already seeing how the first tests with 5G have been done.

Motorola Solutions, in the last editions of the CCW, has not only focused its efforts solely on critical TETRA communications. Some of the most interesting novelties of the American company has been a TETRA critical network compliant smartphone that is also LTE compliant and offers a portable LTE network. This portable network is capable of being started and commissioned in five minutes and has capacity for give very reliable coverage to up to 100 devices in a radius of one kilometer. Another company that has also been offering something similar in 4G as a multimedia critical communications system is Huawei’s eLTE MCCS.

Things are changing and now 4G and 5G is already a necessity, it is a requirement that TETRA users want to have in a single device. In this case, they want to have the advantages of the latest generations of mobile networks due to the low data transmission speed in TETRA and preserve the security offered by the old standard.

MCOP as an alternative to Tetra

TETRA’s path is getting complicated by LTE and the future 5G. In this regard, each country has its frequencies reserved for the deployment of public TETRA networks (police, ambulances, firefighters …) and private (industries, metro networks and more). For this reason, both public administrations and private companies have to cover the costs of deploying these networks. If the enclosure to be covered is small, it will have a small cost, but as the range to be covered expands, that expense also increases.

The National Police and the Civil Guard use SIRDEE (State Emergency Digital Radiocommunications System), a system to which local police officers from different cities have joined from other TETRA systems. For example, in the Basque Country the publicly owned TETRA-based network is called Enbor-Sarea and is used by the Ertzaintza and local police. In the end, everything ends up in a mix of providers and differences between networks that end up trapping the administrations in a provider, with the extra cost that this implies. The SIRDEE program in 2020 turned 20 years old and attends more than 4 million calls a year from citizens who need the attention of the National Police or the Civil Guard.

MCOP wants to liberalize critical communications systems facilitating the choice of providers thanks to the use of open source and the development of customized solutions. The high cost of TETRA deployments and equipment is shared among few companies, which is why the Mission Critical Open Platform (MCOP) was born. We find an initiative funded by the United States Department of Commerce and led by the University of the Basque Country.

MCOP has just released the open source software development kit and a sample application for the development of push-and-talk applications based on the 3GPP specifications. Now the decision will be in the companies and administrations that could save costs and break the chains that bind TETRA providers if they go to MCOP.

5G is going to change the landscape

5G is going to change the critical communications sector a lot due to the Network Slicing. Thanks to it, operators with fifth-generation mobile networks will not have a single network, they will be able to divide it into subnets with different purposes and be semi-independent from each other.

Previously, critical communications had not been able to trust the 3G or 4G networks due to their vulnerability to large agglomerations of users. In large events with many people connected to the same antenna, it is quite common not to be able to make calls. 5G will have a channel dedicated to critical communications and it is going to make a difference.

The Network Slicing that will reach 5G will allow the creation of a system of small parallel networks, so that if one of them is obstructed, the others can continue to function. One of the networks that would separate would be that of critical communications from the rest.

5G coverage is increasing, especially in large cities, but until it is complete, it still has a few years left in which TETRA can be calm, but it will have to evolve and find solutions if it does not want to end up disappearing.

The first tests of TETRA with 5G

At the end of 2019, the world’s first TETRA 5G hybrid network test took place. This test was carried out in China specifically in Guangzhou. The testing company was Airbus which successfully completed the communication tests between terminals and 5G smartphones of the Guangzhou Government Shared Radiocommunication Network and connected with the 5G network of China Telecom of Guanzhou for the first time.

Now, end users from government agencies can experience full interoperability between the two networks by making use of the secure Tactilon Agnet application. Thanks to this app you can use voice and data services without interruptions by connecting to end users of the Tetra network with those of the 5G network. Among the services it can offer we find:

  • Individual and group calls.
  • Courier services.
  • Video and data sharing.
  • Geolocation functions
  • And push to talk.

Tactilon Agnet from Airbus can be viewed as a leading-edge professional collaboration platform and application for mission-critical and business users. This app was installed on various devices for Guangzhou Government staff such as:

  • Smart phones.
  • Secure telephones with dual operation systems.
  • Portable cameras.
  • Satellite smartphones.

The Guangzhou Government Shared Tetra Network implemented by Airbus was the first hybrid network in the Asia-Pacific region. It is interconnected with 4G networks of the three mobile network operators (China Telecom, China Mobile and China Unicom). Finally, with the passage of time and with more and more large cities with 5G coverage, we will be able to see more networks of this type.