The key elements of a critical communications network

03 November 2023

Tero Pesonen, chair, TCCA Critical Communications Broadband Group

Tero Pesonen, chair, TCCA Critical Communications Broadband Group

‘Critical communications’ are exactly that: communications services that are critical for the successful delivery and completion of the missions, tasks and operations of professional users who rely on being in contact when it counts. There are many and varied types of operations which need critical communications. These include public safety and security, emergency services, critical infrastructure, public utilities, transportation, critical industries, and related activities where failures in critical communications would lead to catastrophic degradation of services. This in turn could place critical services and citizen safety and security at immediate risk.

Critical services must be able to cope with high peak demands and provide ubiquitous coverage, as well as extremely high guaranteed availability, reliability, and resilience. Disasters, whether natural or man-made, and other events putting safety of life, property, or public security at risk, can occur anywhere and at any time. They are not limited to areas of dense population. For example, an aircraft or train can crash anywhere along its route and the resultant major incident may be a long way from the closest populated area.

The purpose of critical communications networks is to provide uninterrupted service reliably also under exceptional circumstances meeting the operational requirements.

They are often a tool for enabling other processes and functions to perform – profit generation by the network is secondary. In critical networks commonly the life of the user is at stake – the connection is literally the lifeline.

As well as coverage, sufficient capacity to address tasks or incidents that demand drastically more than normal operations is also critical. The service offered needs to be available at all times with foreseen resilience against loss of power or equipment. In terms of performance for instance group call setup – the capability of bringing potentially hundreds of participants to the same call – needs to appear instant without any loss of content. It is vital to deliver a command of ‘Don’t shoot’ immediately and to all.

Integrity is critical among other security related aspects. Critical communications networks may be used to control power grids, water supply, oil and gas pipelines, or may carry very sensitive personal information such as health records. The information needs to be protected against eavesdropping and manipulation.

Technology is advancing, but the fundamental requirements essentially remain the same. However, the possibilities to fulfil the requirements have evolved whilst at the same time new functional requirements have arisen. Furthermore, whilst in the past such requirements were rather specific to blue light organisations, power utilities and for instance railways, today more and more enterprise and general society processes such as payments demand very similar availability, and even consumers expect coverage, access, and capacity at all times.

2G and 3G mobile cellular networks could not meet the requirements thus fit for purpose designed technologies such as TETRA have been developed and rolled out as dedicated networks for critical communication use. For 4G and 5G network technologies a tremendous amount of work has been done in 3GPP standardisation and elsewhere to enable these networks to address the original requirements, but also the needs of today’s societies that cannot be met by any narrowband technology simply due to the limited bandwidth.

Probably the most significant change is that everything is data – including voice. The public safety radio communication operational model has been voice-centric for the past hundred years. Talk groups have been established to provide a connection between operatives on the field and control centre for commanding and control. The introduction of messaging has enabled exchange of status information and position, but it is a rather limited media working at its best when the information is pre-structured.

The ability to transfer dynamic on the spot-generated data such as video changes the situation. The paradigm can shift to Information Centric Operation where the concept of Information Value Chain can be applied. The data generated in one format may merge with other data and be presented in different forms and shapes to each receiver according to their need and consumption capabilities. Real-time image and video transmission are paving the way into this direction enabling both the leadership and field operatives more accurate situational awareness and more informed decisions.

This type of evolution naturally impacts the requirements for network capacity as well as coverage. When video feed becomes a standard part of each operation then also the capability to deliver it – be it in an underground garage or at the end of the road in wilderness – becomes mandatory. It should be noted that this is end-user organisation and country specific. For many organisations throughout the world the coverage is already provided.

Going forward, in 3GPP the critical communications community represented by TCCA supports strongly the inclusion of Non-Terrestrial-Network (NTN) access to complement other 4G/5G tools to provide redundant connectivity for the users. Vehicle to Everything (V2X) device-to-device communication belongs to the same category.

On the communication itself we expect the introduction of haptic capabilities to mature to enable humans to interact remotely with a combination of senses. These combined with augmented reality as well as virtual reality create interesting operational and technological avenues to explore. Machine-to-machine communication with ever increasing data flow of internet of things (IoT) sensors will provide better situational awareness, predictive operation and much more. At the same time, it requires very sophisticated and balanced artificial intelligence (AI) to manage the massive information amounts. Up-to-date regulation will certainly be a challenge.

What is certain is that society is dependent on communication networks more than ever before – they are already regarded as critical. Attention needs to be paid to their development and operation today and in the future to ensure they do actually meet the critical requirements to keep societies and their citizens safe.