SIGMA has provided communications solutions to more than 1000 mines y tunnels on the five continents. We contribute with innovation to the mining industry, backed by many years of experience installing low-cost and high-performance communication systems. In addition, we provide added value by integrating security and productivity solutions in state-of-the-art communication systems, which give your company a clear competitive advantage. - Underground & tunnel communications - VHF, UHF TETRA or other, 800 P25, P16 or other, 700 LTE 4G - Tagging & Tracking - Passive or active - Rugged IP65 Phones - Radio communication, Portables, mobile, antennas & repeaters.