Advanced Radio Data Information Services (Ardis) sometimes
referred to as the DataTAC network, is a two-way radio service
that is based on Motorola’s RD-LAP technology. It was originally
created and jointly owned by Motorola and IBM to serve
IBM field technicians. Coverage includes about 90 percent of
the urban business population in the U.S with more than 400
metropolitan areas in the United States, Puerto Rico, and the
Virgin Islands.
The network is based on packet-data transfer using data
rates as high as 19.2 Kbps. Some areas may not offer rates as
high as 19.2 Kbps if they are not enhanced with RD-LAP.
Frequencies and protocols are proprietary to Motorola.
Modulation at the physical layer is Gaussian Frequency Shift
Keying (GFSK).