Chapter 14. Mining

The term mining is often associated with old black-and-white images of hard-working men carrying pick axes and carbide lamps into dark underground tunnels and loading ore or overburden into small rail cars. While those pictures are historically accurate, technology has enabled significant progress in the mining industry, specifically around safety, production optimization, and Operational Expenses reduction.

At the most basic level, mining is the process of extracting minerals from the earth. Many types of minerals are extracted today, including copper, gold, silver, lithium, molybdenum, iron, salt, potash, coal, uranium, and precious gems. Most of these minerals, especially precious metals, are rarely just lying on the ground in large chunks, waiting for someone to pick them up. Instead, they are mixed in with other materials beneath the surface of the earth. In the case of copper ore, the average volumetric amount is less than 1%.

To separate and extract the desired minerals, you have to break up large quantities of earth and haul it to a processing facility, where it is further broken down and a variety of techniques are used to isolate the desired material. The techniques and technologies used in mining operations bear many similarities to other industries, such as manufacturing and transportation. As a result, many of the IoT principles discussed in this chapter have relevance beyond mining.

Mining can generally be classified into three major categories: surface mining, underground mining, and underwater mining. This chapter focuses on the first two categories. There are also three main types of minerals mined, in all three mining categories: coal, metal, and nonmetal.

In most countries, mining activities are regulated. For example, in the United States, mining is regulated by the US Labor Department, under the Mine Safety and Health Administration (MSHA) and is also regulated in each state. Working in a mine typically requires specialized training and certification from national regulatory agencies, such as the MSHA. In other countries, the type of mine and exploitation processes are also regulated.

The lifecycle of a mine, which goes far beyond the extraction of minerals, is shown in Figure 14-1. Much time and work is involved in the exploration, planning, construction, operations, environmental monitoring, closure, and reclamation of mine sites. However, this chapter mainly focuses on operations, which is the longest portion of a mine’s lifecycle, often measured in decades.

This chapter includes the following sections:

Mining Today and Its Challenges: This section provides an overview of the mining industry and will help you understand the tools, scales, constraints, and challenges of this industry.

Challenges for IoT in Modern Mining: This section examines the specific challenges in deploying IoT solutions in mining environments.

An IoT Strategy for Mining: This section details the multiple ways IoT can improve mining operations, from increased security and efficiency to lightning and hazardous gas safety, slope and environmental monitoring, and location services.

An Architecture for IoT in Mining: This section details the architecture of an IoT network for mining, from the client side, to the access layer, to the core network, and its security. This section also discusses the application layer and provides examples of how big data changes the way mining operations are conducted.

Many surface mines have several deep pits (see Figure 14-3) adjacent to each other, with long, winding haulage roads that are traversed by giant dump trucks called haul trucks. As shown in Figures 14-4 and 14-5, these haul trucks are machines that make full-size pickup trucks look like toy cars in comparison. Some of the larger haul trucks are capable of moving more than 350 metric tons of material at a time, with 13-foot-tall tires and powered by 4000-horsepower engines. The electric shovels used to fill these trucks (see Figure 14-6) are on the same scale.

The immense size and scale aren’t unique to surface mining operations; underground mines can have hundreds of miles of tunnels, also known as drifts, large enough to fit two city buses next to each other, spanning great vertical distances below the surface. This large scale also means that it can take a very long time to physically get to locations within a mine. From an IoT perspective, this means it could take several hours to get a technician to equipment locations in a site.

Mines are often in remote locations that can be difficult to reach, both physically and electronically. This means the infrastructure needed to support a large-scale mine (electricity, water, communications, rail/road/sea transport) is often not in place or not available at the scale required to facilitate mining production activities. This infrastructure must be put in place by the mine operator or a proxy. Sometimes entire towns, complete with housing, shopping, schools, medical facilities, security, and entertainment, are built and operated by mining companies to support sites that are not within reasonable commuting distances from existing towns. In addition, many mining locations are in locations where extreme environmental conditions such as altitude, humidity, and temperature must be managed and where diseases and fauna may present risks as well.

Open pit mines may look safer than underground mines. However, the forces involved in moving tons of earth and the processes required to extract minerals can be very hazardous. Landslides can be lethal, and monitoring the slopes of open mines is a key safety requirement. In addition, working around gigantic engines is hazardous. From the cabin of these very large vehicles, drivers may not be able to see pedestrians or even pickup trucks. Dust makes the problem worse, even for vehicles equipped with radar. Signaling positions and controlling locations of all workers and all vehicles is necessary.

Weather conditions can also present challenges. Many mines are located in regions of extreme weather. Sudden violent rains may quickly fill pits and holes. When thunderstorms strike, workers are exposed and may be miles away from safe, sheltered buildings.

Mine failures, such as tailing dam failures, can lay waste to vast geographies, and impacts can last for tens to even hundreds of years. Failure to be a good mining corporate citizen will result in governments not releasing new mining leases. Mining operations are concerned about the effect of the operations on the environment and need to closely monitor the weather (and its possible consequences on dust or water pollution, for example), the air, the water quality, and so on.

While general consumers do not know where minerals are located or even care how they are extracted, the people in close proximity to mineral deposits often do. Mining can be a very polarizing topic for a variety of reasons, especially geopolitical and environmental, sometimes involving local radical groups or nation-state–sponsored actors. Mining operators have a huge number of valuable assets. The obvious assets are the minerals that are mined and the equipment used to extract and refine them. However, perhaps not as obvious are assets such as exploration data and other intellectual property.

In some cases, mine operations are the target of political action groups that attempt to stop operations or use a mine as a geopolitical stage to publicize their message. In addition, some mineral deposits are located in parts of the world that are not politically stable or environmentally sensitive. When you factor in additional risks resulting from the remoteness of their operations, large-scale size, inherent safety considerations, and the use of both massive heavy equipment and explosives, physical security and cybersecurity are often top-of-mind topics for mine operators.

Mine superintendent: The mine superintendent is in charge of operations and, ultimately, the profitability of the mine. He is in charge of balancing the investments (in IoT, engines, and people) and the output expected from the mine. The superintendent is interested in any IoT solution to increase profitability and safety or reduce costs.

Engineering manager: The superintendent works in coordination with the engineering manager. The engineering manager is in charge of the equipment of the mine. As such, he or she is interested in any solution that can increase the reliability of the equipment (by providing better monitoring, allowing preemptive maintenance) and decrease the energy consumption related to mining operations.

Operations IT manager: The operations IT manager is in charge of the IT network. Any device that will need to connect through the IT network needs to be reviewed and approved by the IT manager’s team.

Remoteness: In the remote areas where many mines operate, WAN connectivity can be difficult to acquire and is often extremely expensive, relatively low bandwidth, and often subject to high latency and high packet loss. This is especially true when traditional terrestrial circuits are not available and satellite communications links must be used. For many applications, these issues can be addressed with WAN acceleration and compression technologies. However, these technologies are usually not effective for real-time communications applications, such as VoIP and IP video conferencing. In addition, many mines are located in places where there isn’t even cellular coverage, which means the mine operators often need to deploy their own wireless communications infrastructure and may depend on satellite communications for some data services.

Extreme environmental conditions: Mines present a wide variety of extreme conditions in which equipment must operate. Some of these conditions relate to the remoteness of the mines, while others are linked to the nature of the process. Aboveground mining operations often experience extreme humidity and temperatures, both hot and cold, as well as extreme weather, ranging from lightning and wind storms to torrential rains. Many mines, especially in South America, operate at high altitudes, often above 15,000 feet, where the air is much less dense, and equipment cooling effectiveness must be considered. Some mining processes involve corrosive chemicals or flammable and explosive atmospheres. Appropriate equipment certifications or enclosures are required to both keep the equipment safe and prevent fires and explosions. Heavy machinery, especially tracked vehicles such as dozers, create extreme vibrations that could literally shake apart nearby equipment. Such environments require creativity when mounting equipment, such as using rubber grommets to isolate vibrations and neodymium magnets to simplify installation and removal of equipment.

Other environmental considerations include regular and intentional controlled explosions during the process of blasting. Table 14-1 summarizes some of the environmental challenges in mining and possible solutions.

Scale: Mining operations are at an entirely different size and scale than most industries. This often means that a network needs to provide connectivity to hundreds of square miles. To further complicate matters, some mining applications are not IP-based and cannot be routed. Layer 2 connectivity must sometimes be made available across a wide geography. Unlike in any other industry, the nature of mining means that the ground is constantly being moved. Physical locations that act as network distribution points today may be gone tomorrow. The topography of the mine changes daily, which often means the network’s logical and physical topology must be adjusted accordingly. Due to the highly fluid nature of network topologies in a working mine, wireless connectivity is often used for the last mile at the access layer. Even this flexible last-mile access method must undergo lifecycle modifications to accommodate the mine’s changing environment.

Physiological measures: Drivers may be required to wear a wristband (analogous to a fitness tracker) that measure heart rate, breathing patterns, and other factors and generates an alert when these patterns indicate drowsiness.

Behavioral measures: A camera mounted on the dashboard or the rear mirror can measure eye closure, eye blinking pattern (eyes blink slower when falling asleep), yawning, head position, and so on.

Vehicle track measures: Sensors on the truck can measure movements of the steering wheel, position in the lane, pressure on the acceleration pedal, and other factors. Sudden changes reflect drowsiness.

When drowsiness is detected, an alarm can be triggered in the truck or the control center, and the truck can be stopped automatically.

In some open pit mines where terrain topology is relatively stable (that is, the travel path between the extraction zone and the treatment machines is not overturned daily), autonomous trucks are beginning to be used. Figure 14-9 shows an example of one of these autonomous guided vehicles (AGVs).

These trucks are driverless and do not have a cabin. As a result, they do not have a front or a back, and they can offload in any direction. They are programmed with a map of the mine and configured to go to a loading site, where they are loaded with ore. When the load reaches a determined threshold, the truck drives back to a treatment area and dumps the ore into a machine. Sensors and cameras, along with the mine map, help the truck navigate on the site. The operational advantage is that a single remote operator can monitor multiple trucks, and the trucks never get drowsy. However, with the current state of the art, this solution is not practical in sites where the topology changes often because the truck control system would need to be reprogrammed often. These autonomous trucks can be extremely complex and often require multiple sensors, including computer vision, high-precision GPS location, guidance systems, and collision avoidance mechanisms. When it comes to safety, there is a serious risk associated with removing humans from behind the wheel of a 300-ton vehicle. Most autonomous haulage systems rely heavily on IP connectivity and have strict tolerances for network availability.

For example, a monitoring system can be installed on a trailer and positioned on one side of an open pit. The system shoots a 3D laser beam or radar bursts over a 180-degree span, measures the signal response pattern, and compares it to the baseline. Changes in the pattern indicate a change in the slope, usually resulting from a variation in the stability of the terrain. With such a system, an alert can be sent long before an actual landslide event is likely to occur, providing hours or even days of warning. This additional level of safety also allows the mines to operate on more aggressive slopes, which can be monitored for operations safety.

Slope monitoring systems are strategically placed in an open pit mine and require network connectivity to relay the information to the mine operators.

Wireless location services have the advantage of not requiring a GPS signal and can report the position of an appropriately equipped device or worker through a mine network. Some of these solutions require the use of choke points and beacons (to detect when an asset enters or leaves a given location), and others use the signal strength or signal flight time (such as time difference of arrival [TDoA]) of the device on the network to determine the location through trilateration (the intersection of circles). While these solutions may not provide the same location accuracy as GPS (trilateration accuracy varies between 3 and 25 yards, depending on the environment and the architecture), they are helpful in locating assets or workers where GPS signals are not available. This is extremely important during an emergency, as it allows first responders to know immediately where workers are located (without a manual call and count) and concentrate their efforts where rescue efforts are most needed, based on the location of the incident and the proximity of workers to that location.

Beyond emergency cases, worker tracking may be useful to alert a truck driver when a worker is detected on the ground. (Trucks usually include sensors and radar to alert when smaller objects, such as vehicles or people, are detected in the vicinity.) A specific warning can also be displayed in the control room when workers operate in a hazardous location.

Carbon monoxide (CO) is a colorless, odorless, flavorless toxic gas produced by the incomplete combustion of carbon-containing material such as coal or wood. It is a major hazard in underground mines. For many years, workers have been carrying devices to detect CO. Today, IoT sensors can alert operators of the presence of CO anywhere in the mine, in real time, and also show CO buildup trends. An IoT system can also regulate ventilation based on the detection of CO and further modulate it, depending on the presence of trucks (which produce carbon monoxide) and humans. These location systems usually require connectivity to the network and/or actually leverage the existing Wi-Fi network.

One area of great environmental concern associated with mining is ensuring the integrity of tailing ponds. Tailing ponds are very large ponds that hold the waste products of mining, typically finely crushed rock, water, and any chemicals used in the mining process. Figure 14-10 shows an example.

A recent example of why monitoring the integrity of tailing ponds is important is the August 2014 Mount Polly mine disaster, in which a tailing pond failure caused approximately 6.34 billion gallons of mine waste to contaminate the lakes and rivers near the town of Likely, British Columbia, Canada. In an effort to improve the mean time to detection of a tailing pond dam failure, while simultaneously reducing the labor costs of manually inspecting the integrity of tailing pond dams, many mine operators now put IoT systems in place to monitor conditions of the tailing ponds. These systems often use strategically placed ground probe sensors along the tailings pond’s earthen dams to detect signs and symptoms of failure (see Figure 14-11). The systems are often connected wirelessly to the mine’s IP network to report status and potential failures.

Most mines have hundreds, or even thousands, of men and women working in various functions. When equipment fails unexpectedly, these people are often unable to perform their duties. Sometimes these failures are fairly insignificant to the overall operations of a mine (for example, failure of a light-duty truck). Other times, failures are very significant and cause major interruptions in production. This is the case in open pit copper mining when a fully loaded haul truck breaks down and interrupts the flow of ore from the shovel to the crusher. Another similar major event is when the primary crusher seizes because the tooth from an electric shovel made its way into the crusher. These types of incidents can cost a mine a significant amount of money in terms of idle labor, recovery, repair, and restart work.

Predicting equipment failures before they happen isn’t exactly new, but leveraging IoT and big data analytics to accomplish it is new. Many mine operators are now installing IP-connected sensors on heavy equipment to predict and prevent failures before they occur. When this is done correctly, the return on investment can be quick, not only preventing work stoppage due to unexpected failures but optimizing the preventive maintenance costs for equipment.

A very common piece of equipment for mines is the electric rope shovel (refer to Figure 14-6). At the front, a large bucket equipped with metallic teeth digs into piles of soil or ore. There are systems available that can monitor the hardened steel teeth of the bucket and automatically detect and notify an operator when a tooth has come off and might be headed to a crusher. The mine operator can then stop the load and prevent damage to the crusher and the associated work stoppage.

Energy, in the form of electricity and fuel, is one of the biggest operational costs to mines. Nearly all equipment in a mine consumes energy. This consumption ranges from heavy-duty equipment where a single haul truck (depending on equipment type and load) can consume more than 50 gallons of diesel per hour, to the massive amounts of electricity it takes to ventilate an underground mine, run a crusher, and process ore into usable minerals.

Many IoT applications attempt to solve these energy challenges. For fuel efficiency, applications can suggest the most fuel-efficient route for a haul truck (calculating the shortest route and avoiding detected slopes and bumps) or monitor a driver’s behavior and report suboptimal driving patterns. These systems can also record and report any violations of standard operating procedures, such as excessive idling. Detailed tracking of a vehicle’s performance and maintenance can also ensure optimal fuel efficiency.

In underground mining, forced-air ventilation systems require significant electrical power. Through IoT monitoring and analytics, the performance can be optimized along with longevity and energy consumption. These same principles can also be applied to many systems in a mine that rely on electric motors.

Immersive video systems can also reduce the cycle times at mines. While room-based video systems are unlikely to be used in active mining areas, they are frequently used in the business offices of mines and allow remote face-to-face meetings to happen. This technology may not be an option for all meeting situations, but it is a great option for time-sensitive meetings that would otherwise require people to travel great distances.

In addition to a DMZ for the IoT systems, traditional security best practices include network authentication, role-based access controls, regular patching, control plane policing, syslog auditing, and other relevant industry best practices. While it is never possible to completely secure systems from all possible attack vectors, layering security and following industry best practices significantly improves the odds in an ever-changing threat landscape.

Beyond the cybersecurity threats to IT and OT systems, physical security is a major area of concern that must be addressed in appropriate proportion to the risk associated with the mine’s physical location. Theft of assets and physical vandalism, including IoT infrastructure, is a major problem in certain parts of the world. What might initially appear to be failure of remote equipment may actually be theft.

Networking equipment theft, physical damage, or scavenging (an item being “borrowed” for a different function because borrowing is faster than waiting days while new equipment is being shipped) can also have a significant impact on the function of a mining operation. For example, it is much more difficult to recover from the theft of a wireless mesh root access point and all its associated components than it is to recover from simple remote equipment failure. To address this, it is not uncommon for mine operators to put significant physical security barriers in place to combat theft of equipment, as shown in Figure 14-12.

Because of their constantly changing landscape, most mines choose wireless technologies to connect people and smart objects. Many mine sites are remote and unlikely to experience interferences from nearby systems. However, because of the large scale at which wireless technologies are deployed on mining sites, powerful directional antennas are common. Due to the nature of radio frequency (RF) and the possibility of creating unintentional harmful interference with other systems, it is extremely important to coordinate all wireless communication technologies that are implemented at a particular site, regardless of wireless communications category, technology, or application. It is recommended that each mine site proactively track and manage its RF spectrum.

Again, this recommendation is not limited to a specific wireless technology. In fact, a variety of wireless technologies can be used in mining operations to enable communications for IoT. Wireless is extremely important at most mine sites as it is uniquely capable of connecting both stationary and mobile equipment and people. Most wireless networking technologies operate at frequencies in the microwave band, where line of sight is typically required for reliable communications and RF path loss is relatively high.

Wireless can be broken down into two main categories:

Licensed: As the name implies, licensed wireless spectrum requires a government license to operate equipment on an assigned frequency or band. These licenses are typically tied to a physical site location or geography. In mining operations, licensed wireless is frequently used for LMR (a.k.a. walkie-talkies or handie-talkies), long-distance wireless backhaul links (a.k.a. microwave links), and traditional 3G/4G/LTE. Some sites (such as multiple remote sites in Australia) use private LTE, while others rely on agreements with cell operators to deploy a basic cellular connection to the mine site.

Unlicensed: Unlicensed wireless spectrum is regulated by the same government body as the licensed wireless spectrum, but the equipment in this category does not require the owner or operator to individually seek a license to use the equipment within the rules. In the United States, the Federal Communications Commission (FCC) is the regulatory body, and unlicensed transmitters must comply with FCC Part 15 rules. This category includes technologies such as IEEE 802.11a/b/g/n/ac/ah and IEEE 802.15.4, which includes ISA100.11a, ZigBee, and WirelessHART.

Due to their relatively low cost and ease of use, unlicensed wireless technologies are very common in mining applications for data communications, including IoT. While unlicensed frequencies are convenient, care must be taken to coordinate frequency use in a mine to prevent interference. One of the most common sources of wireless communications failures in a mine is interference cause by infrastructure installed by two different teams that did not coordinate their planned frequency usage. For example, a 2.4 GHz wireless video transmitter (non–Wi-Fi) has the ability to obliterate nearby 2.4 GHz 802.11 wireless network traffic and isn’t easily detected without an RF spectrum analyzer.

From an architectural standpoint, a Wi-Fi mesh network is built on the following five components, displayed in Figure 14-14:

Root Access Point (RAP): Mesh access points have wired connectivity to the network to backhaul traffic. In an underground mine, these tend to be close to switch connection points. In an open pit mine, the RAPs tend to be closer to the control center.

Mesh Access Point (MAP): Mesh access points backhaul client traffic via a wireless radio interface, ideally on a different band than the client devices. Many MAPs support connecting wired clients to the network via their local Ethernet interface. All mesh access points (MAPs and RAPs) can be equipped with a GPS module so that control operators can locate them precisely on the mine map. Examples of MAPs deployed in an open mine are shown in Figure 14-15.

Workgroup Bridge (WGB): A workgroup bridge is a dedicated device for bridging wired Ethernet traffic from mobile mining equipment onto the wireless mesh. Some models offer additional features such as support for multiple Ethernet devices, multiple VLANs, and Network Address Translation (NAT)/Port Address Translation (PAT). Often used as security feature and to allow multiple devices to share an IP address, NAT and PAT allow for the translation of an IP address and/or port as a packet transitions through a device.

Serial Backhaul: Backhaul links traverse multiple MAPs; client traffic travels multiple Layer 2 wireless hops to reach a RAP.

Back-to-back or daisy-chaining: For access points that do not contain enough dedicated radios for each function (one 2.4 GHz radio for client connectivity and two 5.8 GHz radios for backhaul), a virtual serial-backhaul MAP can be created with two access points cabled together.

Because Wi-Fi is half-duplex, a MAP cannot simultaneously communicate with the upstream RAP or MAP (the MAP that leads toward the RAP) and a downstream MAP (a MAP farther away from the RAP). The MAP spends some of its time relaying traffic upstream, some of its time relaying traffic downstream, and some of its time relaying traffic for its own 2.4 GHz–connected clients. As a consequence, each hop generates additional delay. A MAP that relays traffic from three more MAPs will proportionally spend more time relaying and less time forwarding its own client traffic than a MAP that relays traffic from a single other MAP. In a multi-hop mesh, when a single radio is used to connect to both the upstream RAP and the downstream MAPs, the available bandwidth is greatly reduced with each hop.

The single 5 GHz backhaul radio architecture also reduces range. Imagine a deployment with a RAP and two MAPs organized in a straight line (that is, a two-hop deployment scenario). The first-hop MAP must use an omnidirectional antenna to reach the RAP on one side and the second-hop MAP on the other side. An omnidirectional antenna has a lower gain than a directional antenna. Such an architecture reduces the possible inter-AP distance. An ideal configuration would include dedicated directional antennas for each direction of the link, for example, using a narrow-beam antenna for upstream connectivity to the RAP and an equally appropriate antenna to service the downstream MAPs.

When designing and deploying a mesh that requires multiple MAP hops, a more efficient architecture is to dedicate a 5 GHz radio for the uplink and another 5 GHz radio for the downlink. This can be achieved with access points that include two 5 GHz radios or by using daisy-chaining or serial backhaul. In this topology, two MAPs are connected through their wired interface, as shown in Figure 14-16.

Upstream traffic is processed through one of the AP 5 GHz radios, called the master, and the downstream traffic is processed through the other AP 5 GHz radio, called the slave. Each AP has a directional antenna for increased range. Traffic passes from one MAP to the other via the Ethernet connection. The result is better overall throughput, over a longer range, as shown in Figure 14-17.

In a standard mesh tree topology, a single RAP connects a MAP tree. It is common to install a second RAP as a backup. In the case of the first RAP’s failure, the MAPs automatically scan all channels in search of another RAP and can discover the backup RAP. Installing a secondary RAP increases the initial cost, but interruption of connectivity is usually costlier than a second AP. Using multiple RAPs is also common for load balancing the MAPs. Because Wi-Fi is half-duplex, each additional MAP reduces the available bandwidth of the other MAPs, regardless of the number of hops. In general, no more than 20 MAPs are connected to any given RAP. Depths of more than four hops are also uncommon.

The information gathered can be used in multiple ways. For example, dust is a critical issue in open pit mines in dry weather conditions. Sensors can help a loader get a sense of the position of a haul truck even through a dust cloud (see Figure 14-18, left side), allowing the loader driver (or the computer, in the case of a driverless loader) to get to the right range and angle before starting to load the truck. A level indicator and refined visualization (see Figure 14-18, right side) can also inform the loader about the quantity of ore loaded to the truck. The truck sensors can also provide feedback to the loader (sending a stop message when the load reaches a defined threshold). At that time, a load complete message can be sent back to the loader (and the mining operation control room) to inform the monitoring crew that the load is complete and the truck is starting to move toward the ore processing zone. This solution enables loading even in dry weather conditions, where the loader driver does not see the truck at all through the dust.

WGBs are access points configured as wireless clients. They can be mounted on vehicles equipped with a battery. Personnel typically also carry wireless devices, such as smart phones, tablets, or specialized wireless IP phones. All these devices have a Wi-Fi function, allowing their location to be tracked through trilateration. RFID tags are also common, especially in underground mines. An RFID tag includes a Wi-Fi card that is configured to emit a basic signal at a regular interval, allowing easy location tracking of each worker. More and more of these RFID tags have advanced functions, such as sensors (vibration, accelerometers, gas, or other), panic buttons, or multifunction signals.

An antenna is a passive device. The amount of energy it radiates depends on the energy inserted into the antenna. Various antennas can send energy in different directions, but the overall amount of energy sent stays the same. A classical comparison is an inflated balloon. You can press it to enlarge it in one direction, but the overall amount of air inside stays the same. Using antennas with higher gain means sending more energy in one direction and, therefore, less energy in the other directions.

A common high antenna gain changes the shape of the radiated energy from a sphere to a flat cookie, as shown in Figure 14-19. The result is a longer horizontal range but at the cost of a shorter vertical range. This is not a problem when the client and MAP antennas are at the same elevation, but it can create huge coverage gaps in open pit mines where there are often large elevation differences.

In the example shown in Figure 14-19, the haul truck’s omnidirectional antenna gain is too high, and the client cannot communicate with the MAP below or the RAP above. So you can see that antenna planning is a requirement for effective connectivity. Antenna types depend on the mine topology and the device to which the Wi-Fi system is attached.

The mounting location of an antenna in also an important consideration. 802.11 antennas need clear line-of-sight to communicate, but they also need to be protected from hazards. A balance between line-of-sight and protection from rock falls and other hazards must be considered. Many installations leverage multi-antennas to achieve optimal results.

The other advantages of private LTE over commercial LTE is that it can be tailored to a mine’s needs, including QoS, synchronized maintenance scheduling of radio networks, and so on. Mining has specific requirements, such as two-way real-time video or fleet autonomy management, which are very different from the requirements of traditional commercial LTE (which is more tailored to one-way video streaming, for example). However, it is important to note that private 4G/LTE solutions require significant planning and investment of resources. In many cases, the mine operator either has to purchase LTE spectrum from the government’s regulatory body or must partner with another private company that owns spectrum. This solution is often used in conjunction with Wi-Fi and wireless mesh (for example, ISA100.11a, WirelessHART) services to provide the appropriate coverage for all assets in a site.

This sample topology is simple but includes a few important details. The MAPs use a PoE output port. This port can be used to connect CCTV cameras that send a live video feed through the backhaul. These images can be used with human monitoring or can be fed into a compute system to analyze traffic patterns on the mine. This information can then be used to optimize operations. Any other devices (such as sensors and other protocol gateways) can also use the PoE output port.

For example, slope sensors are devices commonly connected to the mesh network, and they can be powered from the PoE output port or have their own power source. As explained earlier, slope sensors can be used to anticipate abnormal terrain movements. Analysis software can also correlate the terrain 3D view generated by these sensors with mine mapping software and monitor the mining efficiency. This information can be used to organize the daily operations based on the proximity and density of the target minerals.

In some cases, different teams take care of various aspect of the operations (for example, slope monitoring vs. RFID and personnel location tracking). As a result, several Wi-Fi systems may be deployed and may compete for RF channels. A WLAN controller helps mitigate the resulting interferences.

In the topology shown in Figure 14-21, the operations are local, and no connection to an external network is required. Larger mines may require connections to operations control centers external to the mine site. When the mine is close to an urban center, this external connection may use Wi-Fi, with a point-to-point link to the mine. Cellular connection may also be possible. Sites that are remote need a satellite connection. As shown in Figure 14-22, this type of deployment allows for a different network infrastructure. The mine site may have a limited network deployment, sufficient to ensure proper operations (location tracking and communications, for example), while more advanced compute tasks (for example, slope monitoring, 3D mapping) may be performed in the remote control center.

Security is also a key concern. The previous sections detail physical security, and network security is also critical. In a very competitive market, any disruption of operations and any theft of data can be very costly. When the network is modular, industrial firewalls should be installed between the modules. When the network connects to the business side of the operations, a firewall should perform perimeter security and control remote access to the mine network. Onsite, an AAA server is commonly used to control which devices and which users access the network.

Due to the continuous operating schedule of many mines, where production happens 24 hours per day year round, resiliency and fault tolerance are also very important factors in network design. It is not uncommon for a backhaul link between intermediate distribution frames (IDFs, or intermediate wiring closets) and a main distribution frame (MDF, or central wiring closet) to be severed as a result of routine mining activity. Remember that mines are very dynamic places where the physical environment is in a constant state of change. The network needs to accommodate this constant change and allow extremely fast, if not hitless, convergence in the likely event of a physical link failure. In addition, power in a mine site can be very dynamic. Temporary power loss needs to be taken into account. Power conditioning, uninterruptable power supplies, and redundant power sources should be considered for critical infrastructure.

Topology data can also be fed back to the vehicles on site. For example, GPS sensors located on the blades of a dozer can guide the operator to position the blades optimally, as well as measure and record the new terrain that the dozer movement just created. GPS sensors on shovels can record the exact location of each bucket. This information can be compared to the 3D model of the site to allow the operators to predict with great accuracy how much material and what type of material will be scooped. This information can be used to adapt the production and its output to the state of the market.

IoT is rapidly changing the way mines operate. IoT allows mines to operate more efficiently and more safely than ever before, providing tangible results to mining operators, businesses, and consumers alike. By providing critical real-time information to systems and mine operators, IoT reduces risks that were considered an unfortunate but natural consequence of the vertical activity just 10 years ago. Smart objects can automate processes and make mining easier and safer. By connecting to fog or cloud data processing applications, real-time operations can be measured with very high accuracy and can further improve the life span and efficiency of mining equipment.

While this chapter covers a wide variety of topics in IoT and mining, it is far from exhaustive and is merely an introduction to the subject, based on a snapshot in time. The relevance and value of IoT in mining continues to expand every day.