Roundtable Sponsored by
of how to achieve interoperability
between LMR and LTE networks.
Martin said “this is not too difficult”
and that PowerTrunk is “proposing
solutions to make LMR and TETRA
configurable with FirstNet”. Gray then
asked the attendees to consider the
migration path from LMR to LTE in
North America, the region’s specific
challenges and how coverage and
resilience can be delivered affordably.
Sunk costs, adjacent
agencies and bravery
Mark Pallans said that historically
the commercial/business segment has
driven LMR development, given the
much smaller number of public safety
users, with radios being designed for
business users and then adapted for
first-responders. While he added that
this will hold true for LTE, “you’re
going to have millennials that want
all these features, that’s going to drive
the development of that product a
lot faster than it would if it was just
FirstNet, so when that starts occurring
then the public safety market is going
to not see a need – but they can see the
availability of those extra features…
and this has to be discussed and
thought about”.
Another issue, this time raised by
Horden, is that in US public safety,
“you’re always working with your
adjacent agency that you don’t have
control over, so even if your agency
were to make the cutover to LTE,
you’re still going to be in a coexistence
world because the guy next to you
didn’t”. He explained that there is also
the problem of affordability during
the transition as costs will be higher
than normal when using two networks
rather than one – “my concern is there
are challenging questions nobody is
even asking”.
Gray queried this, given that public
safety agencies’ investment in LMR
at this point is essentially a sunk cost.
However, Horden noted that the shift
to a software-based world has meant
that there is now a significant OPEX
component to LMR “that’s in the 10
per cent range – it’s not going to be
that you can shut off the spigot and
switch over, it’s going to be a costly
transition that needs to be addressed”.
Clemons chimed in: “It will be
interesting when some of the large
state-wide systems come up for
renewal at some stage and then there’s
pressure from government, FirstNet,
and their finance departments.” He
It’s a much more complex
environment that we’re
moving into and complex
environments can always be
taken advantage of by
certain incumbents
that in this case, there is only one
standard, which is MCPTT – in
contrast to LMR, which has seen
competing standards such as TETRA,
P25 and Tetrapol. There was some
discussion of the ETSI MCX Plugtests,
which are working to validate the
MCX standards (MCPTT, MCData
and MCVideo), but as they focus on
early implementation testing, they do
not provide successfully participating
vendors with an interoperability
certificate. Ludwig added that
“currently everyone can claim ‘I’m
MCPTT-compliant’, but nobody can
prove it”.
It is worth mentioning here that
TCCA and the Global Certification
Forum (GCF) are working to address
the issue of MCX interoperability
and certification. Gray discussed his
recent visit to Mobile World Congress
Barcelona where he spoke with test
equipment manufacturers and the
GCF, saying that “there is light at the
end of the tunnel”.
Clemons added: “It’s a much
more complex environment that
we’re moving into and complex
environments can always be taken
advantage of by certain incumbents.”
Steve Barber agreed with him and said
that as a broadband device supplier,
Sepura is being “forced in some
cases to use applications that don’t
necessarily have the APIs or interfaces
available to a device supplier, are
mandated that they run on certain
operating systems which are restrictive
from a functionality perspective and,
therefore, if you’re not careful with this
unstoppable drive towards broadband,
you’re going to end up with a product
and a service that doesn’t do half of
the functionality that an existing
narrowband LMR product can do.”
He added: “We have a lot of
customers around the world that are
giving us that exact feedback – they’re
really concerned because they’re
driven down an Android route or
whatever, they’re driven to a certain
PTT application, but there isn’t the
interfaces within the application to
allow us to supply the functionality to
link it to audio, link it to other parts
of the data, which an LMR user is
used to; he’s used to all these different
accessories and interworking with local
data accessories, which you can’t do.
There’s a long way to go with MCPTT
and mission-critical applications
before we’re anything near the level
of LMR.”
Barber also highlighted that air
interface IOP testing and certification
doesn’t deliver the functional
interoperability that a user “does to
operate efficiently day in, day out – it
just says one device can talk to another
over an air interface and that’s it, so
there’s a more complex layer behind
that which needs to be solved as well”.
There was then some discussion
Federal
Engineering’s Neil
Horden (sitting at
the head of the
table) highlighted
the way that
the transition to
mission-critical
broadband is
complicated by
agencies’ need to
interoperate with
their neighbours
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