Cellular digital packet data
|
|
Cellular Digital Packet Data (CDPD) uses unused bandwidth normally used by AMPS mobile phones between 800 and 900 MHz to transfer data. Speeds up to 19.2 kbit/s are possible.
In the early 1990's, CDPD was large on the horizon as a future technology. However, it had difficulty competing against existing slower but less expensive Mobitex and DataTac systems, and never quite gained widespread acceptance before newer, faster standards such as GPRS became dominant.
As of the year 2004, major carriers in the USA are threatening to shut down CDPD service. AT&T will no longer give out new IP addresses. The threatened shutdown has been delayed several times (the service has a number of entrenched users and no easy direct replacement exists).
External link
- CDPD (http://www.wirelessready.org/nettech_cdpd.asp) from Wireless Ready Alliance