USRobotics V.34 - Manual (Page 211)

COURIER HIGH SPEED MODEMS
J-2 Glossary
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.
Asymmetrical Modulation
A duplex transmission technique which splits the communi-
cations 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 dynamically
reverse the channels during a call if the volume of data transfer
changes.
Asynchronous Transmission
Data transmission in which the length of time between
transmitted characters may vary.
Because the time lapses between transmitted characters are not
uniform, the receiving modem must be signaled as to when the
data bits of a character begin and when they end. The addition
of Start and Stop bits to each character serves this purpose.
Auto Answer
A feature in modems enabling them to answer incoming calls
over the phone lines without the use of a telephone receiver.
Auto Dial
A feature in modems enabling them to dial phone numbers over
the phone system without the use of a telephone transmitter.
Baud Rate
The number of discrete signal events per second occurring on a
communications channel. Although not technically accurate,
baud rate is commonly used to mean bit rate.