Ground-penetrating 'Wi‑Fi' using magnetic induction reaches 100 m underground

Korean research institute ETRI developed a wideband magnetic induction wireless system for underground use.

Field tests in limestone transmitted signals from 100 m underground to the surface at 2 kb/s using a 15 kHz carrier.

Measured performance showed Eb/N0 of 23.98 dB, EVM 14.74%, and a 13.33% efficiency figure.

Researchers said the system could support voice-rate links and suggested potential smartphone integration for underground connectivity.