HIGH PROFILE
Optimising fleets with uninterrupted connectivity
By Chris Mason, VP of Sales for EMEA at Rajant Corporation
Underground mines are some of the most
challenging places to deploy technology in
the world. Despite significant technological
breakthroughs over the years, laying the
foundations required for fibre networks still
requires a great deal of care and management.
Traditional wireless networks must still be
connected at various points to the same fixed
fibre infrastructure that can easily be damaged
but not easily relocated. This creates a problem in
the ever-changing layout of an underground mine.
In such environments, it is vital the network is
able to reach every corner of the mine and adapt
with miners’ movements to provide constant,
uninterrupted communications.
Enhanced connectivity on the surface
On the surface, equipment and infrastructure
must be moved almost daily away from new blast
zones, which means the network that provides
vital connectivity must frequently shift as well.
This creates a problem for traditional wireless
networks that operate from fixed infrastructure.
One innovative solution has seen equipment,
people and vehicle fleets equipped with wireless
technology and sensors to stream real-time data
back to a command centre. This includes
everything from a machine’s current location to its
tyre pressure, enabling operators to gain full
visibility into the health status and performance
of every asset.
Rajant’s Kinetic Mesh ® network architecture
allows open-pit operations to easily introduce,
relocate, or remove network infrastructure. It does
this by placing lightweight BreadCrumb ® nodes
on fixed or moving assets, such as trucks and
shovels, uniquely enabling vehicle-to- vehicle
(V2V) communications between mobile
equipment. That means nodes can be relocated
without causing any downtime, and interference
or signal blockage caused by the changing openpit
environment will not compromise network
performance.
Flexible underground networks
In the most challenging underground environments,
open-pit know-how is leveraged to solve networking
shortfalls where connectivity and throughput
demands are high, but infrastructure places
limitations on how far wireless signals can travel.
Typically, an underground mining network
requires fibre to every device. But installing fibre
in active drives, panels and declines is challenging
to schedule and can create operational and
maintenance nightmares. Also, development, drill
and blast areas can rarely support any fibre
infrastructure, while trucks have been known to
accidentally catch and rip down sections of fibre,
dramatically affecting coverage.
As on the surface, it is possible to create a
complete underground wireless network for
mission-critical data, video, and voice
communications. By using communication nodes
attached to fixed and moving objects within the
mine, a flexible network is created that can go
wherever needed without requiring the installation
of cumbersome equipment and infrastructure.
Predominantly used in hard-rock or metalliferous
mines, but just as easily installed in soft-rock
mines, a combination of Rajant BreadCrumbs and
Poynting wide-band, bi-directional, circular
polarised antennas are being used on more than
200 underground sites around the world.
BreadCrumbs maintain multiple simultaneous
connections between peers and can send and
receive information on different frequencies,
mitigating issues due to interference, congestion,
and equipment outages. Poynting antennas
provide bi-directional coverage with dualfrequency
Wi-Fi connections to assist in
propagating signals around tunnel bends and to
and from moving machinery.
The system is especially useful in providing
expanded coverage in mining production and new
development areas where there might be daily
blasting operations or where existing
infrastructure is minimal. Network coverage can
be easily extended or changed as the mine
develops too. With nodes on all production
vehicles, the network travels with the equipment
into areas where existing networks find
limitations or no coverage at all.
Each node can be a mesh node, an access
point, a bridge or a switch depending on the role
an operator wants it to play. Because each node
operates on two frequencies simultaneously, they
can be connected to the rest of the mesh and act
as a standalone Wi-Fi access point at the same
time. This has proven to be particularly useful for
mine surveyors and geologists who do not have
to wait to get back to the surface to get
connectivity for their phone or tablet.
Networks and automation
By deploying autonomous equipment for drilling
and haulage, mines can achieve production and
safety gains without the presence of an operator.
The challenge is that autonomous applications
are not only bandwidth-intensive, but most
require continuous, uninterrupted communication
otherwise the autonomous vehicle has to stop
due to safety reasons until communications are
re-established. With network nodes attached to
vehicles that can connect wirelessly, via multiple
hops, back to a
primary fixed
network, a mesh
network is the
perfect solution for
sending vehicles to
places people
cannot access.
An example is
Australian Droid +
Robot (ADR). This
Brisbane-based
underground robot and drone survey specialist
was selected to inspect an abandoned mine in
Queensland by the Department of Natural
Resources, Mines and Energy (DNRME). ADR
chose Rajant Kinetic Mesh to enable it to remain
in constant communication with each robot while
underground.
The Collingwood tin mine site, located 30 km
south of Cooktown, had inadequate ventilation
and ground support. There was also visible water
making it a difficult terrain to traverse, yet the
inspection needed to determine the condition of
the bulkhead, which would be out of range of
ADR’s line-of-sight remote control. The mine had,
therefore, been deemed by DNRME to be too
hazardous for human inspection, so it looked to
trial the safe alternative ADR had to offer.
Every ADR robot had a BreadCrumb node onboard
enabling it to independently perform visual
inspections, thermal imaging, laser survey
scanning, gas sensing, and other tasks to identify
and/or operate in the hazardous mine conditions.
The network also uniquely enables these
autonomous systems to communicate V2V and
create an autonomous mesh network to manage
their movements throughout the mine.
Regardless of the issues, Rajant’s Kinetic Mesh
maintained uninterrupted high throughput and
low latency to overcome any obstacles. ADR’s
robotic ‘inspectors’ were enabled to independently
scan, sense, and explore on behalf of DNRME
personnel.
It’s not just equipment that can be connected.
Wi-Fi tags for personnel are emerging as a
solution designed to be used in hazardous work
areas. Underground, like in other industrial
settings, personnel tracking is an essential
requirement to improve situational awareness and
communication – delivering real-time visibility,
which is needed to maximise the safety, security
and productivity of personnel.
With the Rajant-Poynting solution,
underground mines can enhance network
capacity and mobility to run advanced
applications that power greater safety, efficiency,
and autonomy – all without the use of expensive
fibre. IM
26 International Mining | JULY/AUGUST 2020