DEFINITY ECS Release 8.2
Administrator’s Guide
555-233-506 Issue 1
April 2000
Glossary and abbreviations
1652
public network
The network that can be openly accessed by all customers for local and long-distance calling.
pulse-code modulation (PCM)
An extension of pulse-amplitude modulation (PAM) in which carrier-signal pulses modulated by an analog
signal, such as speech, are quantized and encoded to a digital, usually binary, format.
Q
QPPCN

Quality Protection Plan Change Notice

quadrant
A group of six contiguous DS0s in fixed locations on an ISDN-PRI facility. Note that this term comes from
T1 terminology (one-fourth of a T1), but there are five quadrants on an E1 ISDN-PRI facility (30B + D).
queue
An ordered sequence of calls waiting to be processed.
queuing
The process of holding calls in order of their arrival to await connection to an attendant, to an answering
group, or to an idle trunk. Calls are automatically connected in first-in, first-out sequence.
R
RAM

See random-access memory (RAM).

random-access memory (RAM)
A storage arrangement whereby information can be retrieved at a speed independent of the location of the
stored information.
RBS

Robbed-bit signaling

RCRadio controller
RCL

Restricted call list

read-only memory (ROM)
A storage arrangement primarily for information-retrieval applications.
recall dial tone
Tones signalling that the system has completed a function (such as holding a call) and is ready to accept dial-
ing.
redirection criteria
Information administered for each voice terminal’s coverage path that determines when an incoming call is
redirected to coverage.