Scientists from V.I. Vernadsky Crimean Federal University (KFU), together with the regional branch of the Russian Geographical Society (RGS), have developed and tested an underground mobile communication system capable of operating at a depth of up to 2 km. Gennady Samokhin, head of the Crimean branch of the RGS, told TASS about this.
According to the developers, the system is designed for miners and can be used for emergency calls. The principle of operation involves laying a fiber-optic cable, to which a regular mobile phone is connected via a special router attachment.
As far as I know, no one in the world does this.
The equipment was successfully tested in Krubera Cave in Abkhazia – the deepest cave in the world (2224 meters). A mobile phone communication session was organized there from a depth of 2 km. Earlier, in August 2024, an expedition led by Samokhin obtained new data on the cave's depth, which turned out to be 25 meters deeper, confirming its status as the deepest in the world.
In August 2025, Roscosmos organized a teleconference between the International Space Station and Krubera Cave, where a fiber-optic cable had already been laid. The new development also includes monitoring stations with temperature sensors and gas analyzers, which will help quickly detect gas leaks.