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ETHERNET OVER LEAKY FEEDER |
ELF is a solution developed by Minetec Communications to provide ethernet & IP based connectivity over traditional leaky feeder based voice communication systems.
Minetec provide both VHF and UHF digital ready Underground leaky feeder products, all our products offer a migration path to our ELF (Ethernet over leaky feeder) system. So even if you are just after a simple leaky feeder solution you can have the comfort to know that a migration path can be available if you wish to take advantage of our ELF products, supporting technologies such as IP cameras, VOIP phones and other internet access products.
One of the main challenges, particularly in development mining environments is the constantly changing mine layout. This raises problems providing data communications to these new areas, which may be required for equipment operation and/or safety compliance.
An ELF system consists of three types of equipment, represented in Figure 6:
• Integrated Control Unit (ICU) - Provides ethernet connectivity for the ELF nodes to interface with existing network infrastructure. The ICU is responsible for configuration, coordination and bandwidth management of downstream nodes.
• Hybrid Voice Data Amplifiers (HVDA) - Amplifiers are used to boost and extend the range of voice communication frequencies as well as those used by the ELF system. VHDAs are placed at regular intervals throughout the underground infrastructure to maintain a high quality clean signal.
• Node - Nodes provide ethernet connectivity at any point where the leaky feeder system is installed. Installation generally involves installing a branch unit; a simple operation requiring minimal tooling and experience. |
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The ELF solution provides a low-cost, easy maintenance option to provide IP based connectivity to specific locations through the mine. Once the supporting infrastructure is in place, technicians are able to easily install nodes anywhere along leaky feeder path.
DEPLOYMENT OVER AN EXISTING LF INSTALLATION
For an underground mine to support ELF over existing leaky feeder infrastructure, it is necessary the amplifiers be upgraded to support data communications. This allows the RF channels used by the ELF system to be propagated throughout the leaky feeder infrastructure. Next, an ICU is installed in a suitable location where core infrastructure is present. From this point onward, nodes may be placed where ethernet connectivity is required, to support devices such as:
• Tag readers for active and passive systems,
• Environmental monitoring (temperature, gas, humidity),
• Process control such as PLCs and SCADA equipment,
• VoIP telephone systems,
• Any other ethernet based devices.
BANDWIDTH
The current ICU model supports a throughput of up to 30Mbs. If more bandwidth is required in the time being, several ICUs may be deployed to service a subset of the leaky feeder network, with each elf segment providing full bandwidth. Figure 7 shows how multiple ICUs may be deployed to supplement a fibre backbone infrastructure. |
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MAINTENANCE
Underground mining represents its own set of challenges due to its confined areas. Inevitably cable runs and splitter/branch units are damaged due to environmental changes or vehicle interaction. Thus it is of critical importance that the recovery time to get the system operational is minimized.
Repair of leaky feeder is a straight forward process, generally completed by a technician within 15 minutes of locating the fault. To repair a break, few tools such as screwdriver, crescent and cutters are required; compared to the specialized and expensive equipment for fibre repair and termination, such as fusion splicers and cleavers. Once the leaky feeder is repaired, the nodes will automatically begin the synchronization process and establish connectivity with the ICU, typically in less than 60 seconds.
Due to the simplicity of modifying, maintaining and extending leaker feeder runs, ELF is a perfect solution for providing ethernet communications in active mining areas where other mediums such as cat5 or fibre would be too delicate or difficult to repair. |
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 + 61 8 9259 4955
Call today to speak to a Minetec representative |
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