This packet-based technology allows either 9.6-Kbps or 19.2-Kbps data rates over standard analog channels in the 800- to 900-MHz range, by finding and employing unused channels. AT&T's Wireless IP is an example of a CDPD-based service.
CDPD (CELLULAR DIGITAL PACKET DATA)
Meaning of CDPD (CELLULAR DIGITAL PACKET DATA) in English
Jensen's Technology English Glossary. Английский словарь фирмы Jensen Technologies. 2012