Google Patents Data communication over telephone voice channel using DTMF interfaceÄownload PDF Info Publication number US6751303B1 US6751303B1 US10/185,440 US18544002A US6751303B1 US 6751303 B1 US6751303 B1 US 6751303B1 US 18544002 A US18544002 A US 18544002A US 6751303 B1 US6751303 B1 US 6751303B1 Authority US United States Prior art keywords tone dtmf generator alphanumeric alphanumeric character Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google Patents US6751303B1 - Data communication over telephone voice channel using DTMF interface US6751303B1 - Data communication over telephone voice channel using DTMF interface
0 Comments
Leave a Reply. |