Norcat, Rajant achieve digital voice and high-speed data in underground mines

Mesh networks can extend communications deep into underground mines. Rajant has proved this using Norcat’s underground demonstration mine in Sudbury, Ont., for the successful testing of Rajant’s underground digital voice and high-speed data service. Issues such as signal obstacles and harsh environmental conditions to excessive noise and lack of redundancy were overcome – even at the face.

Using Rajant’s Kinetic Mesh wireless technology, Mutualink’s Go Kit with LNK360 software, and Sonim Technologies’ XP10 rugged smartphones, the results allowed real-time communications and data transfer in one of mining’s most challenging environments.

Communications within the mine and from underground to surface have traditionally been enabled using two-way radio frequencies over an antiquated, single leaky feeder radiating cable network. These networks provide basic two-way radio voice communications. However, they do not address communications at the working face of the mine where the production takes place.

Furthermore, independent networks are always required to address air quality management, teleoperations for remote control of equipment and ground control systems.

The proof of concept at the Norcat mine was to demonstrate how to extend wireless communications from the existing leaky feeder system into the working face of the mine. To achieve this, wireless Rajant Kinetic Mesh technology was used as a gateway that crossbands VHF signals to 2.4 to 5 GHz signals.

The success factors behind the solution:

• Rajant Hawk wireless nodes, known as BreadCrumbs, and a Mutualink Go Kit for the infrastructure;  

• Sonim Technologies XP10 rugged smartphones enabled with Mutualink’s LNK360 push-to-talk application; and

• A single VHF two-way radio to connect to the leaky feeder network.

Within the underground mine environment, Rajant Kinetic Mesh BreadCrumbs were strategically placed in the drift alongside and past the existing leaky feeder system to extend coverage into the working face. The Mutualink Go Kit was installed on the surface and into the wired portion of the Rajant wireless network. A second port from the Go Kit was used to interface with a VHF radio, providing a wireless connection to the leaky feeder system.

Within 15 minutes of deploying the aforementioned solution, full wireless communications were immediately established between workers in the mine using handheld portable VHF radios and miners working at the face of the mine, who were equipped with Sonim smartphones.

When a smartphone operator uses the push-to-talk button, the VHF radio channel is activated, and the radio users hear the smartphone’s broadcast over the leaky feeder system. When a radio operator uses the push-to-talk button, the voice signal is broadcast over the wireless Kinetic Mesh network to the smartphones.

Additionally, miners using Sonim smartphones at the working face could share live video feeds to the surface and beyond. This also solves the communication issues with a lone worker at the mine face.

This technology is agnostic and an interoperable solution that can connect to any leaker feeder system, regardless of the frequency band being used. This solution enables new voice-over-internet phones and existing handheld portable radios to communicate with each other. It allows mines to continue expanding present technology into additional areas of the mine while leveraging existing leaky feeder systems.

Employees will benefit from mine-wide communications by simply installing a Rajant BreadCrumb on mobile equipment such as drills, loaders, or trucks, effectively making the machine a wireless hot spot.

For better underground communications, contact www.Rajant.com.