A
ARDIS
A company that provides a cellular packet-switched radio data service in the U.S. Now completely owned by Motorola. (It used to be a joint venture with IBM.) Initially (1984), the network was designed by Motorola for IBM field service technicians. The radio protocol is proprietary (designed by IBM and Motorola). Has about 34,000 subscribers, about 10 times the number that RAM Mobile has. Data transmission is at 4,800 bits/s (using 240-byte packets, resulting in about 2,000 to 3,000 bits/s of user-data throughput) or 19,200 bits/s (in larger U.S. centers) using 512-byte packets, resulting in up to 8,000 bits/s of user-data throughput. Usage charges are per kbyte of data transferred. Sometimes called Datatac. Competes with RAM Mobile Data's Mobitex system and CDPD. Ardis is at http://www.ardis.com/. (Taken from O’Reilly)