Codan Radio P25 Training Guide - Manual (Page 110)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 9: P25 Glossary of Terms Page 102
Delay Time
The sum of waiting time and service
time in a queue.
DES-OFB
Abbreviation for “Data Encryption
Standard - Output Feedback”
Differential Modulation
A type of modulation in which the choice
of the signifi cant condition for any signal
element is dependent on the choice for
the previous signal element.
DNA
Abbreviation for DEC’s “Digital Network
Architecture”.
DPA
Abbreviation for “Demand Protocol
Architecture”
DPSK
Abbreviation for “Differential Phase Shift
Keying” modulation technique. A method
of encoding information for digital
transmission. In DPSK, each signal
element is encoded as a change in the
phase of the carrier with respect to its
previous phase angle.
DQPSK
Abbreviation for “Differential Quadrature
Phase Shift Keying” modulation
technique.
DRT
Abbreviation for a “Diagnostic Rhyme
Test” An audio intelligibility test
DS0
Abbreviation for a 64 kBPS telephone
service
DS1
Abbreviation for a 1.544 MBPS
telephone service.
DSP
Abbreviation for “Digital Signal
Processor” a specialized microcomputer.
DTE
Abbreviation for “Data Transmission
Equipment” (user systems).
DTMF
Abbreviation for “Dual-Tone Multi-
Frequency” - a signaling scheme used
by the telephone system in which two
voice band tones are generated for each
keypad key press.
Dual Mode Equipment
Equipment which will transmit and
receive information using either the
APCO Project 25 standard digital signals
or current analog standard signals
without modifi cation or interfacing
devices.
DVP
Abbreviation for “Digital Voice
Protection” - one of several encryption
algorithms used to provide secure voice
radio transmissions.
ECC
Abbreviation for “Error Correction Code”
See Error Correction.
Ed Interface
The label given to the Host and Data
Interface in the General System Model.
En Interface
The label given to the Network
Management Interface in the General
System Model.
Encryption
A coding of plain text (or clear voice)
into unintelligible forms for secure
transmission.
Error Correction
Digital coding technique for detecting
and correcting information transmission
errors.
ES
Encryption Synchronization information
embedded in a voice data frame