Roundtable Sponsored by
Local LMR frequencies
are controlled by the local
agency. They can approve a
repeater and supervise testing.
They cannot do that with
AT&T’s frequencies
antenna systems (DAS), the neutral
host model, the unit is not owned by
the building owner or managed by the
“code enforcement group, so you’ve
got this dichotomy that hasn’t been
forced through the process yet to see
how it’s going to work”.
This point was picked up by
Rehbehn, who noted that every
jurisdiction takes its own approach
and that “there’s been nothing publicly
stated as to how we’re going to make
that transition. The LMR frequencies
used today at the local level are
controlled by the local agency. They
own that frequency, can approve a
repeater on that frequency and can
supervise testing. The agency cannot
do that with AT&T’s frequencies. So
until AT&T and FirstNet Authority
provide some guidance to an Authority
Having Jurisdiction (AHJ) for local
fire code regulations and enforcement
on how to incorporate FirstNet into
the Emergency Responder Radio
Coverage System (ERRCS), we’re not
going to get anywhere.”
Moving away from in-building
coverage, Martin said that in the US,
at least 50 per cent of police officers
are still using analogue radio because
“the dominant technology for public
safety is extremely expensive”, adding
that a P25 radio can cost around
$5,000-$7,000. Horden later added
that the price of a mid-line radio, in
the quantities that public agencies
buy them in, is around $2,500-
$4,500. Martin went on to say that
his company can offer narrowband
complemented with broadband at a
fraction of this price and that TETRAusing
public safety organisations
elsewhere in the world are paying
significantly less than the sums
mentioned. Sepura’s Barber added
that at the high end of the market, it
is possible to buy 15 TETRA radios
for the cost of a single P25 radio.
Horden noted that part of the reason
analogue continues to be used comes
from operational requirements (as is
the case with firefighters) or economic
reasons. He added that agencies,
particularly in rural areas, are adopting
other technologies such as DMR or
Nexedge to go digital in a way that they
can afford, and this “then creates another
interoperability issue at the edges”.
Barber said part of the cost issue
revolves around “standardisation and
IOP and unless both are strong, you
won’t have a very competitive market to
keep the price down”. Horden added that
there are less expensive P25 radios on
the market, but agencies tend to opt for
high-end builds: “Whether they need all
the ruggedness they’re buying or whether
they’re just impressed with it is another
discussion. The competition in the
TETRA market has driven a lot of that
out. I have customers that have looked at
radios that work identically technically
and still choose the more expensive
radio because that’s the one they trust.”
He added that the person making the
purchasing decision “gets very little
reward for saving a few dollars but is in
significant risk if something goes wrong”.
The direct mode conundrum
Gray shifted the conversation to the
current thinking around how the need
for an equivalent to LMR’s back-to-back/
direct mode will be addressed by missioncritical
broadband. He noted that while
3GPP had delivered ProSe (Proximity
Services), “it’s not suitable. They’re not
going to do anything else in 3GPP, it’s
up to us.” While some have suggested
that there might be some potential
in the V2X communications being
developed for 5G, Gray said that
“with the experience of ProSe, I’m not
putting too many of my eggs into that
particular basket”. Horden highlighted
that a different product to address
this issue would break up the “volume
numbers that drive the cost down,
which is one of the big promises of
moving to LTE”, while also slowing
down the pace of technology revisions.
Clemons added: “In the meantime,
you’re looking at imperfect solutions
perhaps, such as tactical networks,
deployables that have to be taken out
on the fire truck or the police car to
the incident and placed appropriately,
because we know the limitations in
the device itself.” Federal Engineering’s
Horden added multi-network devices
to this list, “which does increase the
cost”. Ludwig emphasised the need for
a standard: “The volumes are simply
too small in mission-critical that we
can afford to fragment this further into
niche markets.”
Gray agreed with him and asked
if simply hanging on to current
LMR devices after their supporting
infrastructure is switched off is an
option. Horden replied, saying
Adobe Stock/Christian Delbert
The high cost of
P25 terminals has
slowed US public
safety agencies’
migration from
analogue to
digital and forced
some of them to
look at cheaper
alternatives
24 www.criticalcomms.com April 2019
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