“Th e hardware and the software are separated, which means
there are more touchpoints than we had in TETRA. We
have pointed out in the white paper that governments and
government-assigned operators for mission-critical services
need to make sure that all touchpoints are under control.
What TCCA can assist with is to make sure that there’s a
certifi cation process between the software and the hardware –
such as MCPTT mission-critical push-to-talk software and
the associated server.”
Jepsen cautions an IOP process will not eradicate issues that
might arise during implementation. “Th ere are still a number
of things that individual service providers in each country will
have to manage directly. Each MNO has diff erent business
objectives and strategies in specifi c regions so, even if you
take the same system from the same vendor in two diff erent
countries, some fi ne-tuning will be needed. You might think
all the networks are the same but, when you dig into it, they
are not. It is not enough for a government procurement service
to say ‘we want X according to 3GPP release Y’, because that
says nothing about how it has been implemented.”
In the context of Mission Critical Services (MCX),
this means that LTE or 5G networks could be 3GPP
standard compliant, but the diff erent implementations and
optimisations mean there could be signifi cant diff erences in
the performance of the network. Th e TCCA whitepaper points
to some 2016 drive testing carried out by Nokia Research
Laboratories. Th e study was not independently verifi ed, but
three LTE networks are shown to have latencies ranging from
40 to 100ms. Th is is just one example of how a network can
conform to a standard yet be implemented diff erently.
Developing a certifi cation process
Th is complex landscape means that developing an
interoperability certifi cation process will be a bigger task
than it was for TETRA. Th e whitepaper explains that
interoperability has diff erent meanings to diff erent people;
protocol interoperability and product interoperability are not
one and the same. TCCA’s defi nition of interoperability is a
combination of protocol and product interoperability that has
been certifi ed by a third party.
Th e whitepaper also lays out where we are with possible
interoperability between vendors. ETSI MCX Plugtests are
Companies are
developing in different
directions, which prohibits
interoperability. That’s why the
paper recommends procurers
should make sure they have
clear agreements with vendors
of what level of interoperability
they have to deliver
the fi rst verifi cation of implementations of new standards and
protocols. Th ey serve as a validation of the standard as well as
early practical tests.
Signifi cantly, Jepsen explains: “Th e plugtests have shown
that companies are developing in diff erent directions, which
prohibits interoperability. Th at’s why the paper recommends
to procurers that they should make sure, in the contracting
phase, that they have clear agreements with vendors of what
level of interoperability they have to deliver.”
Th is adds complexity that could be managed by an agreed
interoperability testing and certifi cation system. Without such
a system, each service provider will need to test all relevant
elements (devices, computers, servers) and their interactions
thoroughly. Th ose tests would then be repeated at multiple
locations. Th is will incur additional costs for suppliers and
users, and vendors will likely implement variants of the same
products that then need to be maintained separately. An IOP
process, TCCA says, will minimise this.
Interoperability can also facilitate cross-border
collaboration. Jepsen says: “Cross-border interoperability is
clearly a need and a wish. We had that need in TETRA as
well. Norway has Motorola Solutions as its supplier, while
Sweden and Finland use Airbus radios. Th ose three countries
are interconnected so people can travel across the border if
they are allowed to do so. Last summer, for example, Sweden
had a lot of wildfi res in its forests and Norwegian fi refi ghters
used their TETRA radios to come across and assist.”
Interoperability certifi cation is still in its early stages, and
TCCA has said in this whitepaper that “TCCA certifi cation
over mobile networks is still some time away”. Now is the
time to collaborate to ensure broadband is brought into the
mission-critical mix in a sustainable, safe and secure way. All
stakeholders need to be given confi dence in these networks
performing as they should – whether that is fi rst-responders
needing to relay information instantly, control rooms having
visibility over their network, or government agencies knowing
their investments are secure.
Broadband off ers so much promise for the public safety
community. Putting interoperability at the heart of the
development of mission-critical services will ensure vendors
can deliver on those expectations. We shall certainly be keeping
an eye on how TCCA’s certifi cation process develops.
March 2020 @CritCommsToday 15