Net-2000™ Voice Codec Unit
User’s Manual
Page 16
Section 3 – Net-2000™ VCU Control
DVSI Confidential Proprietary
AMBE+2™ Vocoder
The AMBE+2
TM
Vocoder is DVSI’s newest low data rate vocoder technology. The Net-2000™ VCU
incorporates the AMBE+2
TM
Vocoder at 4.0 kbps with no FEC. It has been shown to outperform
DVSI’s previously industry-leading AMBE+
TM
Vocoder and AMBE
TM
vocoder technologies. It is
designed to be particularly robust and perform exceptionally well even under bit errors and acoustic
background noise conditions.
AMBE+2 Data Rates and FEC Values
3000 Total bps
AMBE+2 @ 3000 + 0 FEC
3600 Total bps
AMBE+2 @ 3600 + 0 FEC
4000 Total bps
AMBE+2 @ 4000 + 0 FEC
AMBE+2 @ 2400 + 1600 FEC
4800 Total bps
AMBE+2 @ 4800 + 0 FEC
AMBE+2 @ 4000 + 800 FEC
AMBE+2 @ 3600 + 1200 FEC
AMBE+2 @ 2400 + 2400 FEC
6400 Total bps
AMBE+2 @ 6400 + 0 FEC
AMBE+2 @ 4000 + 2400 FEC
7200 Total bps
AMBE+2 @ 4400 + 2800 FEC
8000 Total bps
AMBE+2 @ 8000 + 0 FEC
AMBE+2 @ 4000 + 4000 FEC
9600 Total bps
AMBE+2 @ 9600 + 0 FEC
AMBE+2 @ 3600 + 6000 FEC
AMBE+2 @ 2400 + 7200 FEC
Table 6 AMBE+2 Data Rate
Forward Error Correction (FEC)
As part of the AMBE™ and AMBE+™ vocoder modes the Net-2000™ VCU offers built in FEC.
These two vocoder modes offer a variety of FEC rates ranging from 50bps to 7200bps. High FEC
rates enable the vocoder to maintain acceptable speech quality even at BER rates as high as 5%.
This is a feature that is ideal for mobile communication applications that experience degraded
channel conditions and/or significant bit errors.
