ADTRAN DSU III ARdc User Manual page 117

2047
A pseudorandom test pattern that is repeated every 2047 bits; used to test DSU/CSUs.
511
A pseudorandom test pattern that is repeated every 511 bits; used to test DSU/CSUs.
4-wire switched 56
An AT&T proprietary 56/64 kbps switched digital data service offered by telco service
providers and delivered to users over 4 copper wires. Compatible with the ADTRAN
DSU III S4W and with the DSU III TDM 4-wire Switched 56 TDM option.
asynchronous
A method of data transmission which allows characters to be sent at irregular intervals by
preceding each character with a start bit, followed by a stop bit.
AT commands
Also known as the Hayes® Standard AT Command Set. A language that enables PC com-
munications software to control asynchronous and Hayes-compatible modems. "AT" is
short for attention.
AWG
American Wire Gauge. Standard measuring gauge for nonferrous conductors (i.e., non-
iron and non-steel). The higher the AWG number, the thinner the wire.
BERT
Bit error rate test. A known pattern of bits is transmitted and the errors received are
counted to figure the bit error rate. The idea is to measure the quality of data transmis-
sion. The bit error rate is the ratio of received bits that are in error, relative to the number
of bits received (usually expressed in a power of 10).
61200270L1-1 DSU III ARdc User Manual
Glossary
Glossary-5