(
Cellular
Digital
Packet
Data) An earlier low-speed wireless data network used from the early 1990s to the mid-2000s. Based on IBM's CelluPlan II, CDPD transmitted IP packets in the unused voice channels of analog cellular networks at 19.2 Kbps. If all channels were busy, the data were stored and forwarded when a channel became available. Used for police data networks, public safety terminals and telemetry, CDPD modems were available for laptops via PC Cards and for Apple's Newton and Palm PDAs. See
DataTAC,
Velocita Wireless and
Ricochet.