PMRExpo review
Claudius Pug
After heading over to Airbus
Secure Land Communications’
stand, Michael Wolf, its head of sales
DACH, told me that part of the
rationale behind the partnership was
the realisation that the two companies
are not competitors given Airbus’s
focus on “highly reliable voice
communications”, and that while
Samsung is providing handsets to the
UK’s Emergency Services Network
project, these are LTE only.
Another factor is Airbus’s
expectation that there will be
a long period of coexistence
between narrowband and
broadband technologies for critical
communications. Wolf added that the
“success” of Airbus’s Tactilon Dabat
was the “key driver” for the company
to go further in this direction, and
he also highlighted customers’ desire
for exibility on the smartphone/
LTE side given the dierence in
generation cycles between it and
narrowbandtechnologies.
The road ahead
Tero Pesonen, chair of TCCA’s Critical
Communications Broadband Group
(CCBG), discussed the ongoing work
to create a mission-critical broadband
ecosystem and the timeline for its
development and deployment. He also
outlined the Finnish approach – Virve
2.0 – which will begin in Q1/2019
with procurement for a private mobile
broadband core, along with commercial
4G/5G MNO radio access the
legislative changes to allow Virve 2.0
have been made – Ed. is will be
followed by the procurement of missioncritical
applications in 2020. e target
is to have the Virve 2.0 services tested
by the end of 2022 to enable migration
to begin in the following year. Pesonen
said he expects that TETRA will still
be in use in Finland until at least 2025,
potentially even until 2030 (albeit on a
regionalbasis).
The sky’s the limit
Christian Régnier, head of
communication solutions department,
some problems with a friend’s DMR
network, which meant that it wasn’t
running as well as their large MPT1327
analogue network. He noted the
analogue capture eect, which means
that “if a signal is 6-7dB stronger than
an interfering signal, the higher signal
will prevail and be decoded properly”,
and his experiments conrmed that
DMR requires that the “carrier-to-noise
ratio needs to be 10-12dB better than
the interference signal”.
is means that RF noise at a
site becomes more important when
migrating from analogue to DMR,
creating the need to remove sources of
noise, and Johnson noted that urban
locations can be particularly dicult,
partly due to the widespread number of
cellular sites. Returning to his friend’s
issues, Johnson said that there were two
or three sites which sporadically stop
decoding DMR. “We tracked it down
to the LED oodlights that were at
the sites.” ese had PIR sensors for
security purposes, and whenever they
turned on, the inference from their
inverters “completely wiped out the
DMR system”, despite them being
CE-marked.
Johnson found that some of the
radios on the network that weren’t
operating well were slightly o-
frequency and that “certain radio
manufacturers’ equipment seems
more prone to not working well
with frequency errors even within
the standard’s limits than others”.
He attributes this to how the
manufacturers have implemented their
decoding algorithms. He therefore
recommends checking the frequency of
base stations and terminals, especially
as they start to age, and added that
“realigning some of the mobile stations
on my friend’s network made a huge
dierence to the performance”.
Another source of problems, which
Johnson thinks is the most interesting,
Group Air France-KLM, gave an
update on its private LTE project
(which uses 20MHz of spectrum in
the 2.6GHz band operating in TDD
mode) at Charles de Gaulle Airport,
which was prompted by issues with
using Wi-Fi while scanning luggage
(for example). He said it is currently
awaiting the nal decision from the
French regulator (ARCEP) to see
if it will be permanently awarded
thespectrum.
e company is looking to increase
its eet of mobile devices (principally
tablets, with some laptops for
engineers) to 10,000 in two years,
rising to 15,000 the year after. In
addition, it is currently trialling a single
sim card set-up that will work with
both Air France’s private LTE network
and commercial networks all over
the world, as it would be impractical
for ight crews to have to swap sim
cards each time they landed at a
newdestination.
Régnier explained that this is all
part of the company’s digitisation
projects and that as part of these, it is
looking to shift towards preventative
maintenance and predicting the
connectivity that will be available at
any given site, and will be trialling this
next year with Airbus with the data for
each ight being transmitted over the
private LTE network.
e main driver for this is the
amount of time that can be saved
through preventing incidents that delay
or stop planes from taking o.
Trouble-shooting DMR
Tom Johnson, chairman of the DMR
Association’s technical working group,
delivered one of the best presentations
I’ve ever seen. Taking an in-depth
look at some of the issues that can
be encountered when rolling out
DMR networks, with a focus on the
lessons learned while trouble-shooting
Barbara Held said that
while no decisions have
been made, a future network
model has been proposed by
BDBOS, which takes a
hybrid approach
January 2019 @CritCommsToday 25