CAVE-LINK

Cave-Link is a data communication and measurement system for cave research and mining.
It allows safe data transmission through several hundreds of meters of solid rock.

Beside data recording and transmission, it is also possible to transmit short text messages. If one of the surface stations is equipped with a GSM modem, short messages (SMS) can be sent from and into the cave.

Due to the possibility of automatic forwarding over several Cave-Link stations, even very large distances can be covered.

For communication VLF (Very Low Frequencies) frequencies are used. Distances up to 1300 m were tested but longer distances are likely possible. Tests covered connections within caves and from the cave to a surface radio.

Because all transmissions are secured by checksums and automatic query, no transmission errors are possible.
A bad link (great distance, atmospheric noise, interferences) just increases the communication time, but will not cause transmission errors.