Codan Radio P25 Training Guide - Manual (Page 116)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 9: P25 Glossary of Terms Page 108
RF
Abbreviation for “Radio Frequency.”
RF Sub-System
The RF infrastructure which is bounded
by the fi ve open APCO Project 25
interfaces and three standard computer
network gateway interfaces. It is the RF
equipment and related non standard
peripheral equipment which provides
a standardized RF communication
channel. One of the APCO Project 25
interfaces is the Common Air Interface
(CAI).
RS-232
An asynchronous, serial, data
transmission standard that defi nes
the required sequence, timing, and
hardware interface.
RS
Reed-Solomon error correction code.
RTP
Abbreviation for “Real-time Transport
Protocol”.
SAP
Service Access Point, where a network
provides a service.
Setup Delay
The time in ms required to actuate
equipment for transmission and
reception.
Signal
The detectable transmitted energy which
carries information from a transmitter to
a receiver.
SINAD
Abbreviation for “SIgnal plus Noise And
Distortion” to “noise and distortion” ratio.
SMRS
Abbreviation for “Specialized Mobile
Radio Service.”
Squelch
A radio circuit that eliminates noise from
the speaker when no transmitted signal
is present.
STC
Abbreviation for “Sinusoidal Transform
Coding” A voice coding technique
(analog to digital voice conversion).
Subscriber Unit
A mobile or portable radio unit used in a
radio system.
Sub-System
A defi ned portion of any organized
assembly of resources and procedures
united and regulated by interaction or
interdependence to accomplish a set of
specifi c functions.
System
Any organized assembly of resources
and procedures united and regulated
by interaction or interdependence to
accomplish a set of specifi c functions.
T1 system
A digital communication system
designed to handle 24 voice channels
at 64 kBPS each. Digital transmission
media to support 1.544 Mbps.
transmission speed.
TCP
Abbreviation for “Transmission Control
Protocol.” ARPAnet developed transport
layer protocol.
TDMA (Time Division Multiple Access)
A communications technique that uses
a common channel for communication
among multiple users by allocating
unique time slots to different users.
Telnet
Terminal-remote host protocol
developed for ARPAnet.
TGID
Abbreviation for “Talk-Group Identifi er.” A
sixteen BIT fi eld identifying talk-group of
the radio message.
Throughput Delay
The total time in ms between the
initiation of a voice or data signal, ie.
push-to-talk, until the reception and
identifi cation of the identical signal at the
received output speaker or other device.