Table of Contents
Advertisement
Accunet
Address
Alarm Indication
Signal (AIS)
Analog
Anti-Streaming Timer
Asynchronous
Asynchronous
Transmission
Baud
BER
BERT
Bipolar
Bit
APPENDIX B
GLOSSARY
Data-oriented digital services from AT&T Communications, including Accunet
T1.5, terrestrial wide-band at 1.544 Mbps (formerly called T1); Accunet Reserved
T1.5, satellite-based channels at 1.544 Mbps primarily for video teleconferencing
applications; Accunet Packet Services, packet-switching services; Accunet Data-
phone digital service (DDS), private-line digital circuits at 2.4, 4.8, 9.6, and 56
kbps.
A sequence of bits, a character, or a group of characters that identifies a network
station, user, or application; used mainly for routing purposes.
An AIS is a keep alive signal of continuous "ones," and is required by the net-
work in the absence of a normal DS1 signal. In response to receiving an AIS,
LOS, or OOF from one side, the CSU returns a Yellow alarm, and transmits an
AIS to the other side. An AIS is transmitted until the error condition clears. An
AIS is also called a Blue alarm.
Transmission employing variable and continuous waveforms to represent in-
formation values.
Ability in a modem to ignore a Request to Send (RTS) signal from a data termi-
nal if it is held on for longer than a specified amount of time.
Transmission that is not related to a specific frequency or to the timing of the
transmission facility; transmission characterized by individual
bytes with start and stop bits from which a receiver derives the necessary timing
for sampling bits; start-stop transmission.
Serial transmission of data in which each character is individually synchronized
by the use of start and stop bits. A start bit precedes and one or more stop bits
follow continuous information bits. Also called start-stop transmission. There is
no definite time relationship between transmission of successive characters.
The maximum number of signaling elements, or symbols, per second that are
generated; may be different from bps rate as several bits may be encoded per
symbol, or baud, with advanced encoding techniques such as phase-shift keying.
Bit Error Rate.
Bit Error Rate Test, or tester.
The predominant signaling method used for digital transmission services, such
as DDS and T1, in which the signal carrying the binary value successively
ternates between positive and negative polarities. Zero and one values are repre-
sented by the signal amplitude at either polarity, while no-value "spaces" are at
zero amplitude; also, polar transmission.
A binary digit, the representation of a signal, wave, or state, as either a binary
zero or a one.
B-1
characters
or
al-
Advertisement
Table of Contents
