In the past, authorities, public safety organizations and industries often used analogue dedicated lines to supply radio transmitter/receiver stations and control stations with audio and control information. In many cases these lines are no longer available or have become prohibitively expensive.

The Audio Processing Gateway (APG) from RADIODATA makes it possible to transmit analog audio signals transparently over cost-effective time division multiplex lines such as E1 or ISDN as well as over IP networks as Voice-over-IP. Optionally, the APG's digital signal processor can process and evaluate the data. This makes it possible, for example, to evaluate and acknowledge FMS telegrams, generate and evaluate tone sequences or encode/decode sub-audio tones.