10 October 2022

Paul Ward, director, ETELM

Private 4G/5G communications offers an exciting opportunity for mission critical users – the move towards high-speed broadband services will enable new, advanced applications and offer significant operational improvements for users. However, there will still be a demand for traditional PMR technologies….so can the industry gain more than just the improvement in data services?

TETRA is still the most advanced digital trunked communications system for mission critical users today and sets the standard for voice and group communications but will never be able to offer the high-speed data services that are essential for today’s critical workers. As organisations look towards the next generation mobile communications, there is an opportunity to reflect on how different technologies can continue to be viable for users.

Traditional narrowband PMR technologies will be required well into the future….issues of affordability, spectrum availability, cell coverage and re-use of existing subscriber equipment are all likely to be factors. We believe that a hybrid approach to technologies is the ideal solution to allow users the best choice; and a fully integrated, single network solution will always be a better solution than gateways to separate networks.

The TETRA standard was developed over 20 years ago, and one of the major benefits was the interoperability between subscribers from different manufacturers, however the lack of interoperability at the infrastructure level was (and still is) a frustration for clients. This was not an issue in the consumer 4G market as 3GPP standards allow all LTE eNodeBs to co-exist on the standard LTE Core. As a TETRA vendor, users regularly ask if our base stations can be used to extend an existing system (from a different manufacturer) – sadly the lack of an open networking standard adopted by all manufacturers, meant that full interconnectivity was not possible (apart from using a basic gateway interface)…this proprietary issue created difficulties for users, particularly where security is at stake. The ability to seamlessly select from a range of different vendors, and different technologies on the same core network is an ideal approach.

Recent global emergencies should focus mission critical users on the importance of fast, secure communications and the ability to rapidly deploy the most appropriate technology for any situation and in any geographic area is essential. A perfect example is where ETELM working with B-LIFE deployed a system combining both TETRA and 4G for COVID emergencies in Italy.

The B-LIFE project required a rapidly deployable health laboratory to effectively respond to emergency public health issues – this is particularly pertinent to COVID but also for co-ordinating vaccination programmes, and for outbreaks of other viruses such as ebola, where dealing with any isolated outbreak is critical to avoid the spread and save lives. A similar solution is also adapted for emergency services and military applications whereby the user can benefit from secure TETRA voice communications deployed instantly in the field, with advanced mobile applications linked to command centres obtaining important data and making assessments in real-time. This solution is often based on single cell systems, where 4G (and 5G) has limited coverage, so having TETRA for voice communication and a ‘4G Bubble’ for broadband data services, connected to the central monitoring systems gives the benefit of both technologies.

As an industry supplying highly secure, national infrastructure we must collectively work towards a future where our customers are given the option to select the most suitable technology (or combination of technologies) and not left in a position where they are locked-in to a supplier or service, and we have a responsibility to ensure migration paths are more seamless and less complex than they currently are today. The 3GPP model is perfect in this respect.
If one assumes that the demand for PMR technologies will continue (even in the ‘next-G’ world!), it is essential that vendors look at offering an equivalent fully integrated, single network solution for users. There is no technical reason why several different technologies cannot inter-operate on the same core network, this will reduce the costs and increase the options for users, and simplify the architecture by avoiding gateways and separate interfaces. ETELM’s 4GLinked is a trailblazer in this regard as its TETRA base station can co-exist with eNodeB’s on the LTE core network….so how can we take this opportunity to revolutionise how vendors of different technologies co-operate in the future?

The technical solution is possible, and lessons can be learnt from the network standards established by 3GPP for the mobile consumer market – the 4G and 5G Core network is internationally standardised and all base stations from different vendors inter-operate on the same network. This gives operators the ability to select suppliers based on a competitive market, and the ability to switch suppliers quickly should the need arise. This competitive approach has been a major factor in the rapid rate of deployment and technology advances in the consumer communications market.

An opportunity now exists for manufacturers of all standard PMR technologies to adopt the same approach and develop their technology into the 3GPP standards for core networking – LTE Core, 5G NR…. this could create a single eco-system for all mobile communications and allow users to select and mix technologies based on cost, service and user requirements. 4GLinked TETRA base stations adopt this approach as they can connect directly to any LTE Core network in the same way as any LTE eNodeB, by utilising the LTE-S1 connectivity standard. This allows our TETRA system to be deployed over the same, single network core solution alongside 4G and future 5G base stations. The solution has been tested at 3GPP Plug tests and already deployed in many different scenarios for emergency services.

As the 3GPP networking standards for 4G and 5G are open, any vendor can develop the same solution into their base stations meaning that we can all benefit from the advances in core networking and allow inter-system and inter-technology solutions over a single core. The technology is available but commercial issues need to be overcome – this is where users can influence vendors and ensure that they never find themselves locked-in to proprietary networks.

Once technology becomes interoperable the next challenge for large national networks is how to deploy their service – privately owned or operator managed? The choices are available, and certainly operators will have a large part to play since they already have much of the national infrastructure established. However, once again users must ensure that there is a competitive environment – there is no point in having open standards in technology, if users are forced into single sourced managed services….so it is important to ensure that options exist with other operators so that services remain competitive – again a challenge for highly secure networks and one that needs to be carefully managed.