Modernising critical comms

05 October 2023

As technical capabilities expand, how are critical communications networks evolving? We asked the experts for their insight and what the future might hold

Critical communications networks save lives every day, delivering uninterrupted service reliably, under exceptional circumstances.

“Critical communications networks must be available 24/7 and in particular when other networks are failing, supporting the ability to communicate during disasters, major incidents, times of civil unrest or when an element of critical national infrastructure becomes unavailable,” says Duncan Swan, chief operating officer, British APCO.

Data-centric design
While the fundamental requirements for a critical communications network are the same as ten years ago, the possibilities to fulfil the requirements have evolved.

“Though group voice communications remain vital to fire, rescue, and law enforcement, innovative LTE-enabled data applications have arrived that deliver functionality significantly improving operational safety and effectiveness,” says Ken Rehbehn, principal analyst, CritComm Insights. “Critical communications systems based on legacy land mobile radio technology, such as TETRA or analog radio, do not have sufficient bandwidth to support most new data capabilities. That gap drives a push towards LTE systems supporting mission-critical services.”

Swan agrees that the underlying technology that comprises these networks has changed significantly: “using new technology opens up a wealth of new possibilities to communicate… data and video have an ever-increasing role to play to improve efficiency and effectiveness – in particular in determining how best to respond to a situation.”

Though interest is growing, video plays a limited role, opines Rehbehn. “Video feeds from drones frequently flow over unlicensed spectrum that is not public safety grade.

As agencies embrace LTE delivering critical communications with QoS, priority, and preemption, the use of video becomes more practical. For example, US FirstNet users with Axon body-worn cameras can now send video to the control rooms when a police officer removes their gun from a holster. This video-enabled perspective provides a crucial situational status that cannot be quickly transmitted by voice alone.”

“They say a picture paints a thousand words – and data and video can both provide greater situational awareness; allow those relying on critical communications networks to receive real time information that is relevant to their current situation; and monitor the wellbeing of workers in difficult situations,” adds Swan.

“The public safety radio communication operational model has been voice centric for the past hundred years,” says Tero Pesonen, chair, TCCA Critical Communications Broadband Group. “But 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. Real-time image and video transmission are paving the way into this direction enabling both the leadership and field operatives to have more accurate situational awareness and take more informed decisions.”

“Data access is an important capability in today’s critical communications networks,” agrees Rehbehn. “New LTE networks provide high throughput that supports mobile data terminals linked to computer-aided dispatch systems and general office desktop systems. Data systems are also essential in today’s emergency medical service, enabling electronic patient reporting and hospital communications.”

With the rise of data, security becomes an increasingly pressing concern. “Security is paramount to protect the network and services,” adds Martin Duggan, principal network architect, Systal. “Automation is increasingly being used for repetitive tasks and has enabled integration to multiple systems enhancing the efficiency and effectiveness of the services.”

Capacity vs coverage
Network operators design LTE networks to be commercially viable, which means some thinly populated or mountainous regions may not have universal coverage. Nations investing in LTE-based critical communications networks have required service providers to expand coverage to these areas, but some remote areas remain underserved.

“Beyond geographic coverage challenges, in-building coverage may be the weakest link in future LTE-based critical communications networks. Energy-efficient building design blocks radio signals, LTE included. Without in-building coverage systems to get signals in and out, emergency workers may be cut off when they need connectivity the most,” says Rehbehn. “Legacy land mobile radio systems operate at lower frequencies, offering better penetration into and out of structures. Nations that move from legacy land mobile radio to LTE may quickly discover that the new network fails when responders travel to the bottom of a large structure.”

“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 the needs of present-day societies are not feasible for any narrowband technology to meet due to the limited bandwidth,” shares Pesonen.

“There’s a real dilemma as to how much you spend (in both money and time) both hardening a network and ensuring it has the right level of coverage and capacity,” says Swan. Lower frequency solutions provide better coverage as well as penetration into buildings, “but that is at the expense of a true broadband capability,” adds Swan.

“The meshing of different networks is one way to achieve better coverage and functionality – as well providing the hardening of the overall solution through diversity.”

A critical tomorrow
Critical communications networks will continue to evolve as new capabilities become reality.

“We see a use case for higher bandwidth, reduced latency and additional endpoints on the network, there will be more data to process, and attack vectors will increase meaning the network will need to provide additional levels of security by use of ML & AI,” says Duggan.

“We expect the introduction of haptic capabilities to mature to enable humans to interact remotely with a combination of senses. These combined with augmented and virtual reality create interesting operational and technological avenues to explore,” says Pesonen. “M2M communication with ever increasing data flow of IoT sensors will provide better situational awareness, predictive operation and much more, but at the same time it requires very sophisticated and balanced AI to manage the massive information amounts.”

Swan agrees that diverse technology will be key going forwards. “We can expect device evolution that incorporates mission-critical services over LTE with push-to-talk, video, and data alongside a non-LTE radio that provides a backstop when LTE networks are not reachable,” says Swan.

Additionally, a growing role for satcoms as LEO constellations expand, enabling ‘vehicle as a node’ concepts, will emerge. “Communications hubs mounted on a vehicle will select the most effective and lowest cost path for communications from a range of options: land mobile radio, LTE, mesh connectivity, and satellite links. The concept can already be found in Australia, and we expect it to gather momentum,” concludes Rehbehn.