Filling the gap between existing telecom infrastructure and the requirements of VOD

Important financial benefits of a real-time optimized VOD system come from the capability to modulate all ventilation components, including auxiliary fans. To enable real-time optimized VOD, mines must deploy infrastructure for pervasive real-time tracking, monitoring and control.

Tracking requirements

SCADA requirements

These requirements exceed those of standard operations and communications applications and are not met by telecommunications infrastructure deployed in underground mines, be it leaky feeder, Ethernet, Wi-Fi or a mix of these technologies. In particular, diesel machinery and personnel must be continuously monitored and tracked with stope-level precision and safety-critical reliability.

To bridge the gap between the installed infrastructure and the requirements for ventilation on demand, the Newtrax battery-powered wireless mesh network technology is deployed as an extension to existing telecommunication infrastructure to enable three critical upgrades:

• Real-time tracking of diesel equipment and of personnel with stope-level precision
• Real-time monitoring of diesel engines and of air quality sensors
• Reliable detection of vehicles and personnel passing through check points

The Newtrax battery-powered wireless mesh network tracks in real-time the precise location of the machinery for workspace air flow requirement calculation. It optionally reads the air flow and quality instrumentation and transports the signal up to the HMI and the simulation. It carries the fan speed and regulator position set points from the optimizer and HMI to the physical devices.

Data transfer to and from the HMI can use existing leaky feeder, RS-485, or Ethernet/Wi-Fi installed in the mine. The Newtrax networking technology is especially well suited for an hostile environment such as the active face of an underground mines:

1. Self forming and self healing network protocol ensures installation, extension and maintenance is simple, quick and low cost.
2. Decentralized architecture enables multiple redundant and resilient linear topology options.
3. Ad hoc multi-hop communications between nodes are possible without going through central server or a network coordinator.
4. Industrial-grade Frequency Hopping Spread Spectrum (FHSS) Wireless RF links for range up to 100-400m with 122dB omnidirectional RF link budget, pseudo-random hopping over 64 frequencies, link-level acknowledgements and automatic retries
5. Use of 902-928 MHz provides better RF propagation than 2.4GHz frequency band
6. Backhaul to surface over analog leaky feeder or Ethernet/Wi-Fi.