Codan Radio P25 Training Guide - Manual (Page 117)

P25 RADIO SYSTEMS | TRAINING GUIDE
Chapter 9: P25 Glossary of Terms Page 109
TIA
Abbreviation for “Telecommunications
Industry Association”
Time-Out-Timer
A function that limits the transmission
period to a pre-defi ned time. The user
will automatically stop transmitting when
the timer goes off after the pre-defi ned
time.
TPDU
Abbreviation for “Transport Protocol
Data Unit.”
Transmission Delay
The time in ms required for transmission
of a voice frame or data packet through
a communication channel.
Trellis Code
Type of error correcting code for digital
modulation
TriBIT
3 BITs grouped together into a symbol
for a trellis code
TRS
Technical Requirements Specifi cation
Trunk
A single transmission channel between
two points that are switching centers or
nodes, or both.
Trunked (system)
Systems with full feature sets in which
all aspects of radio operation, including
RF channel selection and access, are
centrally managed.
UDP
Abbreviation for “User Datagram
Protocol”.
ULP
Abbreviation for “Upper Layer Protocol”.
Layer above TCP.
Um Interface
The label given to the Common Air
Interface reference point in the General
System Model.
VOCODER (Voice-Coder)
A type of voice coder. Usually
consisting of a speech analyzer and
a speech synthesizer which convert
analog speech into digital signals
for transmission and digital signals
back into artifi cial speech sounds for
reception.
VSELP
Abbreviation for a “Vector Sum code
Excited Linear Predictive” voice coding
technique (analog to digital voice
conversion).
WAN
Abbreviation for “Wide-area Network”
X.25
The CCITT three-layered interface
architecture for packet switching
connecting a DTE to a DCE.