A packet data protocol standard for sending wireless data, it was developed for use on cellular phone frequencies. It transmits data in packets on unused cellular channels (in the 800MHz to 900 MHz range). This technology offers transfer rates of up to 19.2 Kbps, quicker call set-up, and better error correction than modems on an analog cellular channel. Too confusing? Basically, CDPD is a way to send and receive information over wirelessdevices.