Nordics
Before the adoption of the ISI
standard, interactions were
more complicated
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 from
each 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 missioncritical
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.
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 rescue
operations 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,
March 2020 @CritCommsToday 11
Photo credit: Johan Eklund
The northern
regions of
Scandinavia
are sparsely
populated and
inhospitable, so
implementing
comms networks
is difficult and
costly, but
satellites might
provide an option
in the future