An inband signaling modern communicates digital data over a voice channel of a wireless telecommunications networks. An input receives digital data. An encoder converts the digital data into audio tones that synthesize frequency characteristics of human speech. The digital data is also encoded to prevent...http://www.google.de/patents/US20020097706?utm_source=gb-gplus-sharePatent US20020097706 - In-band signaling for data communications over digital wireless telecommunications networks
