Codan Radio P25 Training Guide - Manual (Page 108)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 9: P25 Glossary of Terms Page 100
BER Threshold
The level at which the BIT error rate
exceeds the error correction capability
and communication fails in a digital
system.
BIT
Acronym for binary digit.
BIT Rate
In a BIT stream, the number of BIT
occurring per unit time, usually
expressed as BITs per second or BPS.
BIT Stuffi ng
A method used for synchronizing BIT
streams that do not necessarily have the
same or rationally related BIT rates, by
adding non-information (“stuffi ng”) BITs.
BPS
Abbreviation for BITs Per Second, a
data rate measure.
BR
Base Radio, a reference designating a
base station radio.
C4FM
The acronym for a 4-ary FM transmitter
which uses QPSK modulation to work
with a CFDD compatible receiver.
CAI
Abbreviation for Common Air Interface.
Call Congestion
The ratio of calls lost due to a lack of
system resources to the total number of
calls over a long interval of time.
Call Delay
The delay experienced when a call
arriving at an automatic switching device
fi nds no idle channel of facility available
to process the call immediately.
Call Set-up Time
The overall length of time required to
establish a circuit switched call between
users or terminals.
Capture Effect
An effect associated with the reception
of frequency modulated signals in which
if two signals are received on or near the
same frequency, only the stronger of the
two will appear in the output.
Carrier Noise Level
The noise level resulting from undesired
variations of a carrier in the absence of
any intended modulation.
Carrier Squelch
A radio receive mode of operation that
causes the receiver to unmute in the
presence of a received signal.
CDMA
Abbreviation for Code Division Multiple
Access. A coding scheme in which
digital information is encoded in an
expanded bandwidth format. An access
method that allocates each user a
coded set of channels on which to send
outgoing information frames.
CELP
Abbreviation for a “Code Excited Linear
Predictive” voice coding technique
(analog to digital voice conversion).
CFB
Abbreviation for a “Cipher Feedback” an
encryption synchronization method
CFDD
The acronym for a receiver which
detects QPSK-C compatible modulation.
CFDD stands for Compatible Frequency
Discriminator Detection.
Channel
A single unidirectional or bidirectional
path for transmitting or receiving, or
both, of electrical or electromagnetic
signals.
Channel Rate
The data rate at which information
is transmitted through the channel,
typically stated in BITs per second
(BPS).