GLOSSARY
16550 UART The fastest type of UART that is currently available.
Adaptive Speed
Leveling (ASL) Business Modem V.32 bis and V.32 terbo modems detect improved line
conditions and shift upward again to the next higher speed. The
modems at both ends of the connection adapt independently, each
detecting and adjusting to line conditions. ASL keeps the mo dems
online, always operating at the highest possible speed, and constantly
ensuring data integrity.
analog signals Continuous, varying waveforms suc h as the voic e tones carr ied over
phone lines. Contrast with digital signals.
answer mode A state in which the modem transmits at the predefined high frequency
of the communications channel and receives at the low frequency. The
transmit/receive frequencies are the re-verse of the calling modem
which is in originate mode.
application
(application program) A computer program designed to perform a spec ific func tion, such as a
word processor or a spreadsheet.
ARQ See Automatic Repeat Request.
ASCII American Standard Code for Information Interchange. A 7-bit binary
code (0's, 1's) used to represent letters, numbers, and special characters
such as $,!, and /. Supported by almost every computer and terminal
manufacturer.
ASL See Adaptive Speed Leveling.
asymmetrical
modulation A transmission technique that splits the communications channel into
one high speed channel and one slower channel. During a call under
asymmetrical modulation, the modem with the greatest amount of
data to transmit is allocated the high speed channel. The modem with
less data is allocated the slow, or back channel (450 bps). The modems