Critical Communications World 2019 2019 WORLD
THREE DAYS IN KUALA LUMPUR
The fi rst of CCW 2019’s three days
The Critical Communications Today team reports on the highlights from Critical Communications World
provided visitors with a series
of masterclasses, designed to
get them up to speed with some of the
central issues taking place within the
industry. Streams included ‘Tetra Today
and Tomorrow’, ‘Pushing the Boundaries
of Innovation Across Transport, Utilities
and Industry’, ‘The Global Flavour of
Critical Broadband’, and the two-part
‘Critical Broadband Masterclass’.
One key presentation came from
IHS Markit’s directing analyst, critical
communications, Ken Rehbehn, which
took place during the Critical Broadband
Masterclass stream. Focusing particularly
on devices, he provided something of a
reality check in relation to mission-critical
broadband, highlighting the industry’s
dependence on chipset manufacturers
(and Qualcomm in particular, in
FirstNet’s case).
He noted that ProSe (proximity-based
services – 3GPP’s version of TETRA’s
direct mode) has a signifi cant impact on
modem design, while both QoS Class
identifi ers for MCPTT and MCVideo and
support for eMBMS (Evolved Multimedia
Broadcast Multicast Services) that were
added in Release 13 have moderate
implications for modem design.
Referring to eMBMS as a critical
component for mission-critical broadband
communications, Rehbehn said: “So
much of our PTT experimentation has
been with unicast traffi c fl ows from
the network to the end-users and I do
not believe that this scales up. If you
have 15 emergency services workers
at a scene and they can hear each
other’s radios, if the traffi c is delivered
in unicast to each of the units and is
not synchronised then there’s going
to be noise. It’s also an ineffi cient
use of network resources, especially
in a location where you have scarce
resources, such as a remote area where
a temporary isolated network needs to
be established. eMBMS has not been
embraced by mobile network operators
due to the costs of putting it in play.
However, AT&T is committed to making it
part of the FirstNet network; I believe it
needs to be part of every network going
forward to get MCPTT to work properly.”
He added that ProSe’s performance
might not be adequate, given that other
elements of the cellular RF chain are
poorly positioned to enable back-toback
coverage (power amplifi ers being
limited to 125mW and the use of internal
antennas) – “I don’t believe that even if
we get a modem that supports ProSe
that the physics are going to allow that
support to actually be useful.” That
said, Rehbehn noted the way in which
5G vehicle-to-vehicle communications
share some characteristics with TETRA’s
direct mode, though this is seeking to
tackle a different problem. A member
of the audience said that an enhanced
proximity-based service is already
commercialised in South Korea’s PSLTE
network, with a Korean chipset
vendor and a device from a Korean
Android device manufacturer and that
during a fi eld test last year it achieved
a line-of-sight device-to-device range of
several kilometres.
Rehbehn also drew attention to the
fact that support for mission-critical
features on the LTE module side is still
in its early days, with most modules
on the market being aimed at general
purpose IoT applications, rather than
mission-critical functionality. He also
said: “It’s not enough to say: ‘I’ve got
a modem that supports mission-critical
communications.’ You have to factor in
the other elements of the band-specifi c
radio chain that are needed for a device
to work in your country.” Rehbehn
concluded with a “glint of optimism”
that the interest in private broadband
networks for non-public-safety verticals
“may help stimulate a virtuous cycle of
innovation that drives us forward”.
This was followed in the same session
by Ahmed Laslah, business development
director, mission critical and private
networks, at Ericsson. Looking at the
broader strategic picture, he explored
the different models for mission-critical
networks. For instance, dedicated, shared
RAN with dedicated spectrum usage;
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