Does LMR have a place alongside FirstNet?
LMR networks have a long history of fulfilling the requirements
of Public Safety communications. These days, it is common for
agencies to use public carrier broadband networks alongside
LMR networks. Each of the networks fulfills a need—LMR
provides mission-critical voice communications, while broadband
networks provide a large pipe that enables a range of data-intensive applications to be run. Is FirstNet the Holy Grail that
addresses both needs? Possibly, but not in the short term.
Is an LMR network by itself enough?
It is, for the minimum level of mission critical voice functionality,
and in the case of digital networks, low-bandwidth data
applications as well. However, some data-heavy apps that require
a bigger pipe, can provide efficiencies far and above basic
mission critical voice. For example, streaming video provides
a large amount of situational awareness to people who are not
present at the scene. In-field reporting saves officers from having
to go back to the station to file reports and allows them to have
a greater presence in the field. Are those greater efficiencies
something that you need now? That is something for each
individual agency to decide and to prioritize, based on their
Can an LTE network be the sole source of
Public Safety voice communications?
In business-as-usual conditions, maybe sometime in the future.
Mission critical PTT over LTE is still developing, but it has been
defined within the LTE standard by 3GPP, so it should become
widely available. Advances in the LTE core mean that Public
Safety communications can be partitioned and prioritized over
public communication, so that in an adverse event like
an earthquake where a lot people will be attempting to use the
network, Public Safety agencies will be able to communicate
without having to compete with the public for bandwidth.
However, LTE physical infrastructure is not as robust as LMR
infrastructure. LMR’s greater coverage means that fewer base
stations are required, and these can be hardened by both
physical protection and battery back-up/generator. LTE sites
have less range and are more numerous, so it is not economically
practical to have a large amount of battery back up for them, or
to provide a great amount of physical protection where they are
So, can communications that rely on a network that is not
hardened be considered mission critical? The use of LMR
and FirstNet in conjunction provides greater coverage and
redundancy than just using one network alone.
LMR can also communicate in simplex mode from radio to
radio, when infrastructure is not available. Device-to-device
communication is specified in the LTE standard with ProSe
(Proximity Services), but it remains to be seen how well this
feature will work. Also, will the range be sufficient when using
this with devices that don’t have an external antenna and
a significant amount of power output?
In addition to physical security, how secure
is a nationwide network from digital attacks?
LMR networks are, for the most part, standalone networks that
aren’t connected to each other. And many LMR networks are not
IP-connected. This means that there are fewer points of entry
for malicious actors who are attempting to hack into the system.
FirstNet will undoubtedly have the levels of security that a Public
Safety network of this type warrants. However, there are multiple
points of entry and it will be a big target for hackers and others
seeking to cause harm and chaos.
When will FirstNet be built out in your area?
AT&T are using their existing commercial network and spectrum
to get started, but this coverage is not comprehensive. There
is still a large of number of coverage gaps due to the fact that
Public Safety agencies still need to operate where it doesn’t
make economic sense to build out a commercial broadband
network. In addition to the $6.5 billion of government funds
allocated over the next five years, AT&T will spend another $40
billion building out the network over 25 years.
Whether that level of funding is adequate to finish the job
remains to be seen, but the other key point is the timeframe.
Twenty five years is a long time, and represents two potential
lifecycles of an LMR network. The reality is that for some parts
of the nation, LMR networks are going to be the workhorse of
Public Safety communications for some years to come.
TWENTY FIVE YEARS
IS A LONG TIME AND
OF AN LMR NETWORK. ”