Share This Page

For those readers that have never worked underground, trust me when I say “It’s Hard”. It is hard to work there, it is hard operating systems there, it is hard to install technologies there and it is hard to maintain systems there. Difficulty aside, communications systems for underground are vital for one primary purpose and that is safety, and although important, everything else is secondary.

In this blog, I am adding some context to the technology discussion around solving the challenges that are emerging in interoperability between legacy and emerging communications solutions to create the experience of a simplified solution without sacrificing the essential reliability and performance required for your safety and production applications.

Originally, my thoughts were to discuss solving the problems associated with last mile connectivity but upon reflection, while last mile connectivity is the end result, what we are talking about is really addressing the problems of integration between different communications technologies and why choosing the wrong migration or solution path can lead you further away from a simplified, maintainable and interoperable outcome.

Extending your underground network seamlessly

The basics in communications for underground

Historically, (more than 20 years ago) comms for underground voice was delivered via wired infrastructure to telephones mounted on the wall or through two-way Leaky Feeder systems (a cable system running along your tunnels simulating a very long antenna) and data was typically delivered through fibre networks to fixed locations

Since the emergence of Wi-Fi technologies in the early 2000’s, many specialist underground vendors started producing their own products and applications around Wi-Fi technologies. This also included solutions for data and power distribution and connection, Voice over Wi-Fi, Wi-Fi-based personnel and asset tagging, asset health, production reporting apps etc. The emergence of Meshing technologies such as Rajant has enhanced the capabilities even further by enabling Machine-to-Machine, infrastructure wireless extension and in Rajant’s case, with minimal latency or throughput artifacts (this means you can have many hops in the network without any significant impact to performance).

And now with the introduction of LTE over Leaky Feeder systems emerging, it is becoming very clear that there are potentially multiple communication technologies at play that can exist in a single operation, many of which remain disparate and under-leveraged.

Introduction of LTE in underground

LTE underground has been accepted very quickly as a strong contender for replacement of legacy two-way radio and will likely be adopted as the solution of choice for wireless distribution for many applications. This can be attributed to two things: one is that like traditional leaky feeder, two way systems power and comms are passed through and managed along the one cable, and so, there is a high level of comfort in the way the system can be maintained with the current site resources; the second is that high capacity wireless coverage is distributed down the same length of radiating cable with the power used for powering downstream booster amplifiers. So it is perceived as getting more out of a single system (Voice, Data and Power).

In concept this is true and is highly desirable, however the architecture of the technology does not enable data connectivity to many current machine based applications as simply as Wi-Fi systems do today because these applications operate on different layers of the OSI model, which introduces a layer of complexity into the solution as it requires IT networking professional skillsets to design, deploy and support. That doesn’t mean it’s not a good idea, it just means there is higher level skillset required to support the solution and there is a greater risk of extended downtime when the system breaks (and you can be guaranteed the system will break on a weekend during night shift) as the troubleshooting process now potentially involves not just the on-shift sparky that traditionally repaired the broken leaky feeder cable or the blown up BDA (Bi-Directional Amplifier) but also an IT professional to resolve an issue.

Although, these types of risks can usually be mitigated through proper design commissioning and change control processes, reducing outages to those typically caused by cable damage and other typical underground scenarios that are well understood today. Needless to say there is a piece on culture change and change management that the miner needs to consider as with the introduction of any new system.

Extending your underground network seamlessly

So, moving on to our real operational scenario of making multiple systems work together as seamlessly as possible.

Let’s consider the scenario where we need to extend these new LTE networks beyond its coverage area to create an immediate last mile solution? Well, the answer is quite simple in concept and we do it all the time in our consumer lives. We hotspot our phone so we can share our LTE out to our friends.

Yes, we are extending network coverage over Wi-Fi. Now this is a fairly trivial function on our smart phone and it appears seamless from a user’s perspective. However, the applications we are using on our phones are designed to traverse these two disparate networks seamlessly (LTE and Wi-Fi networks operate on two different layers of the OSI model and do not natively inter operate unless there is some intelligence in between them). Those smartphone apps are all designed this way from the beginning to hand off between the disparate technologies, whereas your mining applications I referred to earlier are generally not, and therefore, there is a level of application and network integration that needs to be built into the solution to manage the connections between the disparate networks and the reliable transport of the data across them.

So how do we solve this problem? Well at 3D-P as usual, there is always more than one way we can provide a solution depending on what you already have or what you may be planning to have, your plans for migration and desire for simplicity and robustness.
After a number of years studying, researching and testing the use cases for both open pit and underground operations, we have developed a fit for purpose solution, regardless of the wireless technology or complexity of your existing or planned infrastructure.

The 3D-P Intelligent Endpoint hybrid meshing solution enables interoperability between LTE, Wi-Fi and Rajant Mesh networks, and at the same time creates a simplified and robust transport layer for all application traffic with seamless hand-off between LTE and Wi-Fi based technologies. The solution not only hotspots and seamlessly hands off your mining applications from an LTE network like you experience with apps on your smart phone, but it also enables you to daisy chain radios in quick succession when needed to instantly extend a fixed network (wireless or wired) for kilometers without any noticeable throughput loss or changes to latency. At 3D-P, our goal is to produce solutions that are easy to use, to create a transparent and highly reliable end user experience that “Just Works”.

For more information on how 3D-P can help you with your last mile connectivity challenge, contact us today.

By Categories: LTE for Mining, Underground Mining, Wireless Technology