It was 1993 when Mark Rose, Founder of Tunnel Radio of America, got the call that dramatically changed the trajectory of his company’s growth.

In the five years since its founding, Tunnel Radio had been working with mining operations, installing the wireless systems Rose and a partner had developed to ensure uninterrupted communications between teams above and below ground. But now a railroad was calling, looking for help achieving the same uninterrupted communication, this time between both ends of a train as it passed through a long tunnel. Before starting Tunnel Radio, Rose had been a helicopter pilot in charge of a fleet of bush pilots delivering supplies to teams working on the Alaskan oil pipeline.
source= https://railway-news.com/pioneers-reliable-railway-communications-tunnel-radio/