SEE Telecom is an expert of radio connectivity in tunnels and metros since 2000 for safety and operational networks with more than 1500 km equipped in 30+ countries. We provide innovative services and software for first responders and tunnel operators to support them in their critical and maintenance missions thanks to our integrated systems : conventional push-to-talk VHF, UHF, TETRA and P25 radio networks, mobile radio technologies 3/4/5G, Internet of Things (LoRa, OpenThread), and geolocation (GPS, Galileo).