The Nordic countries have a long-time attachment to Terrestrial Trunked Radio (TETRA), with Finland’s plans for its first network dating all the way back to the early 1990s due to the high cost and weak security of its analogue predecessor. Today the standard is used across the region, not just in public safety but also in mining, oil and gas, utilities and the transport sector. Oslo and Helsinki metros embraced TETRA (in the latter case replacing simple use of mobile phones) to connect control rooms with drivers, rescue and maintenance staff. Then came Helsinki’s city tram network.
Several well-known large organisations are happy with TETRA and continue to back it – yet they are still opting to upgrade their existing networks. For example, Danish wind farm operator Ørsted selected Atcom and Celab in August last year to develop an integrated communications system for its HR2 site in the North Sea.
The upgrade will bring improved call quality and data transfer between the site and head office in Esbjerg, while also enabling a better overview of workers’ precise location, whether they are active in the port, on board a service vessel or at a wind turbine.
State-owned oil giant Equinor (formerly Statoil) has been using an IP-based TETRA system, including a pager service, on the Johan Sverdrup field. Sogn and Fjordane Energy (SFE) is utilising Norway’s Nødnett TETRA network using Sepura TETRA radios supplied by the latter’s Norwegian partner Wireless Communications AS.
Elsewhere, Wireless Communications has supplied Sepura STP9000 TETRA terminals to the Norwegian Road Administration (NRA), which also uses Nødnett. This has enabled NRA to extend coverage in mountainous parts of the country, replacing an old analogue system that failed in tunnels and suffered with limited signal range, leaving many of the region’s skiing villages without any coverage. The Haukeliester traffic centre now has direct contact with all maintenance staff, since radios are installed in each vehicle.
Cross-border interoperability
The Nordic region is the first in the world where multiple countries have implemented cross-border interoperability, including common talk groups for public safety users. Norway, Sweden and Finland have their own national TETRA networks for public safety communications (known as Nødnett, Rakel and Virve respectively).
A new cross-border system established between all three countries in early February last year is based on the standardised Inter-System Interface (ISI) functionality, enabling police, rescue, customs, defence forces and border guards to communicate effectively.
This co-operation has been particularly useful along the sparsely populated 1,010-mile (1,630km) Norway-Sweden border, where public safety personnel have a tradition of collaborating with peers in the neighbouring jurisdiction.
Before adoption of the ISI standard, interactions were more complicated due to the absence of any common communications system. The Virve network (37,000 users) was first connected to its Norwegian equivalent, Nødnett (55,000 users), in November 2018, while Rakel (80,000 users) and Nødnett had been connected earlier in 2016/2017.
Despite the much-vaunted success of the initiative, a great deal of user preparation and training was involved; users from each country had to agree on common procedures, as well as learning how to use the system.
“We’ve learned that it’s important to facilitate meetings between the users from the different countries, and encourage them to perform exercises,” says Nina Myren, deputy head of department at the Department of Emergency Communications in the Norwegian Directorate for Civil Protection (DSB), which oversaw the deployment.
The main users – police, health and fire services – had different ways of going about this, so DSB has offered continued support when needed. “It was a complicated project to establish ISI first time,” admits Myren. “It involved two vendors, two operators and user representatives fromeach country. As with all development projects, there were some issues. But the co-operations went really well between all participants.”
Crucially, the users did not have to purchase new terminals – these simply required a software upgrade and to be programmed with the correct talk groups.
Tapio Savunen, Finnish manager for Airbus’s Secure Land Communications, has welcomed the shared network model – and co-operation over organisational boundaries – as a good foundation for future development of the sort of mission-critical mobile broadband (MCMB) services that can be delivered by 4G LTE.
Of course, the evolution towards MCMB solutions puts a question-mark over the future of ISI itself. “In the distant future when all countries have been completely migrated to MCMB solutions, the ISI likely will be replaced with a 3GPP-based solution,” reckons Savunen.
However, he expects the transition phase to be difficult, since the process can take several years even within a single country. There also remain significant coverage issues in areas with low population density and the mountainous regions of the north, causing governments to search for alternative solutions to build satisfactory radio connectivity.
The possibilities around satellite communications have gained some attention, most notably in a report from October 2019 ordered by Finland’s Erillisverkot and written by research organisation VTT.
Below: Finland is furthest ahead in migrating its emergency services to 4G LTE, but each country is planning to rely on commercial mobile networks for most of the RAN infrastructure.
Satellite future?
The VTT report recognises that the rough baseline for an acceptable service delay is the observer’s ability to perceive response time. The response times of human senses are in the order of ~100ms, ~10ms and ~1ms respectively for auditory, visual and tactile information.
For a mission-critical services (MCS) user, it is vital to experience an instantaneous reaction after a service-calling button is pressed in an end-user device to avoid any extra delays while conducting a time-critical mission. In addition, a high service availability close to the ‘five nines’ is of paramount importance.
VTT surmises that “space communications can become a good candidate for MCS, provided the performance is sufficient and there is an effective integration solution available”. In addition to voice services, satcom technologies have been used previously for population early warning systems, of which Cospas-Sarsat is a strong example.
This system was developed for search and rescueoperations and locating emergency beacons in maritime scenarios. Many countries have their own emergency population warning systems based on satellites, most famously Japan’s J-Alert.
In fact, satellite communications (using Iridium) are already used by several Finnish emergency authorities as a back-up technology and in hard-to-reach locations. However, the question remains as to whether it is possible to make improvements from a user perspective.
A considerable boost is expected from recent 3GPP/5G non-terrestrial network (NTN) specification activities, which are still at an early stage (as Release 17 efforts begin), to bring the terrestrial and NTN communities closer together. Another milestone will come from low-orbit mega-constellation satellite frameworks.
The road to LTE
In Finland, MCMB project Virve 2.0 is in the procurement phase but should be complete by 2022. Services will be based on the mobile network operators’ (MNO) networks. In Finland there is no dedicated spectrum reserved for PPDR, but the spectrum allocated to MNOs will be used.
Finnish legislation obliges MNOs to provide priority and pre-emption services for PPDR users, with a new electronic communications services law coming into force at the beginning of February this year to ensure service availability and quality for users even in times of peak network congestion.
Under the new system there will be one primary MNO, while others will provide national roaming for PPDR users. Suomen Erillisverkot Group, the state-owned operator ofthe Virve TETRA network, has been appointed operatorof Virve 2.0.
The procurement process is now in the second of two phases – the first covering a dedicated core network for PPDR and MNOs’ radio access network services, the second involving mission-critical applications defined by 3GPP standards (MCPTT, MCVideo and MCData). However, even upon completion it has been accepted that the TETRA-based first generation of Virve will continue to be used by the authorities and security services until at least 2025.
As for Norway, DSB is working on a concept study for long-term replacement of Nødnett (present contracts expire in 2026), provisionally named Next Generation Nødnett (NGN). A dedicated broadband network for mission-critical users is no longer an option since the decision in December 2017 to make Norway’s 700MHz band available for commercial operators.
Mobile network operators Ice, Telenor and Telia have proposed a number of solutions, including: a secure MVNO with a state-owned core; a single turnkey provider using its infrastructure and possibly national roaming; and several competing turnkey providers. The most likely option looks like being the ‘secure MVNO’ model where the state owns the core network.
The Swedish approach to 4G migration differs from the Finnish and Norwegian plans. In Sweden, part of the 700MHz spectrum has been set aside to wait for a final decision on its use. In a report from the Swedish Ministry of Justice, a dedicated LTE network for PPDR use has been proposed.
The spectrum allocation would be 2 x 10MHz with an additional 2 x 5MHz in the longer term – when the current TETRA network, Rakel, is no longer operational. The initial deployment will resemble that of Virve 2.0 in Finland, with the Swedish network starting as an MVNO.
This approach involves a government-owned core network with radio access services provided by MNOs. The introduction of the dedicated radio access network will take place step by step. In Sweden, the final decisions on spectrum usage and the exact operational model of the MCMB network are imminent.
Meanwhile, in Denmark, MCMB procurement is yet to take place. The contract for the Danish TETRA network (known as SINE) is due to expire in 2021 and the Danish administration is now in the process of tendering communications services for public safety.
The Danish police are already making use of various applications on smartphone devices. These communications (including real-time data, video and images) take place over a mobile operator’s LTE network, with a security solution to protect the confidentiality of the data.
Elsewhere, the Finnish police are at the forefront of using drones in everyday operations, with more than 400 trained drone pilots in service and 200 aerial vehicles in official use. Superintendent Sami Hätönen of Finland’s Police University College regards their introduction as “the start of a success story”.
Meanwhile, some verticals are beginning to make their own moves into 5G independently. For example, Boliden’s Kankberg mine in Sweden installed a 5G network underground with the help of Telia in July last year.
Ultra-low latency offers prospects for remote operation of machinery, closer process monitoring, vehicle tracking for safety and higher productivity, local data handling and the introduction of myriad other industrial Internet of Things (IoT)-related applications, such as energy-efficient smart ventilation systems – all on the same voice and data network.
Flight of fancy
Drones are used not only to track fleeing criminals, but also in crime scene investigations, search and rescue operations and crowd surveillance – most famously the Trump-Putin Summit in Helsinki in July 2018, Finland’s presidency of the Council of the European Union (between July and December last year) and during Independence Day celebrations.
Drones are equipped with diverse sensors, including video cameras, thermographic cameras, LED lights and more. When Virve 2.0 services are available in Finland, police drones are expected to be used in conjunction with the new network.
The Finnish Border Guard is piloting a more advanced drone solution, following a successful trial period at the close of 2017. While the organisation was known to have around 50 drones in operation at first (utilised in a range of surveillance activities as part of field tests and personnel training), the new system will be activated automatically on receiving an alert from existing border control technology.
This recognition system utilises artificial intelligence (AI) for the interpretation of images in order to ascertain whether a human or animal is moving in the target area. This device transfers the images over a wireless network to the hub, from where they are transferred to the control room. The Border Guard’s Valvonta 2 project last year also explored the possible use of sensor-equipped unmanned vehicles in the northern reaches of the Baltic Sea.
The scenarios covered included surveillance of sea and water areas, waterways and the archipelago, monitoring and checking of containers, oil tanks and other stationary facilities at ports, and environmental accident management. Drones remove the need to dispatch a helicopter or boat.
The other Nordic countries are also quite far along in embracing drones for search and rescue purposes. With the cost of helicopters proving increasingly restrictive, the Norwegian authorities were already exploring UAVs as long ago as 2016. The first exercise took place in conditions of -15°C in Bykle Setesdal, involving 250 personnel from the police, fire department, International Red Cross, army and air force. The Altura Zenith system gave an aerial overview with optical and thermal cameras – transferring images to base camp and police command using mobile networks.
In late 2017, Copenhagen Police deployed a drone as part of its surveillance operations on cannabis buyers in the Christiania area – an effort that resulted in the detention of 60 people on narcotics charges and the seizure of nearly 12 kilograms of the drug.
Since then, UAS Denmark has recognised the appeal of reduced cost (over the use of helicopters) and improved safety offered by drones in road and rail inspections (removing the need for rope inspectors), as well as the capability to monitor longer stretches at lower cost, and for effective image capture even in overcast conditions.
Two-way radio will continue to have a place in public safety and various other verticals for some time yet, but for the emergency services in the Nordics the emphasis over the next few years will be on managing their migration to mission-critical 4G LTE.
