Can high-speed, collision-free data travel through kilometres of underground tunnels – where radio signals weaken and conditions are harsh? With Sigma’s advanced Data Over Leaky Feeder (DOLF) system and RACOM’s RipEX2, the answer is yes.
https//www.racom.eu/ru/case/underground-communication-solution
Challenge: Modernising Communication in Harsh Underground Environments
For more than 30 years, Sigma has been a leader in underground communication systems. But industries such as mining and tunnelling now demand:
- higher data rates for automation and monitoring
- low-latency, collision-free communication
- reliable connectivity through rock, dust and complex tunnel geometry
- compatibility with a wide range of RTUs and underground devices
- a future-proof solution that can support long-term operational growth
Traditional low-bandwidth or voice-only systems were no longer sufficient. Sigma needed a radio platform capable of high modulation rates and robust performance in underground conditions.
Solution: RipEX2 + Leaky Feeder Enables High-Capacity Underground Networking
After extensive evaluation, Sigma selected RACOM’s RipEX2 radio modem operating in the 150 MHz band as the core communication engine for the DOLF system.
Key technical advantages:
- 256QAM modulation for high-capacity data transmission
- Base Driven Protocol (BDP) enabling deterministic, collision-free communication
- strong penetration characteristics of the 150 MHz band
- seamless support for large numbers of RTUs
- robust design suited for harsh and remote underground environments
System architecture highlights:
- surface-based RipEX2 head-end units communicating with underground repeaters and RTUs
- leaky feeder infrastructure guiding radio signals through extensive tunnel networks
- advanced sleep modes to extend energy autonomy at remote locations
- tight integration between Sigma engineers and RACOM technical specialists
Results: A Breakthrough in Reliable Underground Data Transfer
The DOLF system powered by RipEX2 has delivered major improvements:
- stable, high-speed communication where traditional systems struggled
- dramatic increase in available throughput for underground operations
- reduced downtime thanks to highly reliable hardware
- easy integration of diverse underground RTUs
- strong customer feedback and global interest in Sigma’s solution
Sigma is now scaling the DOLF solution worldwide, confident in RipEX2’s long-term reliability, performance and underground suitability.
