Industrial Voiceband Modems
Voiceband modems, though obsoleted for most public networks, still are relevant for data transmission over private “telephony type” infrastructures, and voice channels of radio links.
Copper wire cables that are conditioned for use of voiceband communication are often not suitable for the use of DSL modems that require a much higher bandwidth.
Also for communication over “dry” copper cable, voiceband modems are still relevant because of the ability to operate over long distances.
Why use voiceband leased line modems?
Pure galvanic “dry” copper connections (as needed for baseband modems) may not always be available.
In some areas, voiceband transmission is still the only option because of the lack of a long distance digital infrastructure.
Voiceband modems can be used over long-distance lines and voice channels of radio systems.