Apco Vocoder Selection; Figure 7 Voice Source; Figure 8 Rate Selection - Digital Voice Systems Net-2000-P25 User Manual

Net-2000™ Voice Codec Unit
User's Manual
Figure 7 Voice Source (VOIP Mode Only)
4-Wire
When the 4-Wire voice source interface is selected, the Net-2000™ VCU expects the analog voice
signal input on the RCA jack (Item 7 in Table 1 Rear Panel Connectors). The unit outputs the
analog signal on the output RCA jack (Item 6 Table 1 Rear Panel Connectors). The Net-2000™
VCU always outputs the audio to both the 4-Wire and Handset output regardless of which voice
source is selected.
Handset
When the Handset voice source interface is selected, the Net-2000™ VCU expects the analog voice
signal input and output on the RJ11 jack (Item 8 in Table 1 Rear Panel Connectors). The output will
also be on the output RCA jack (Item 6 Table 1 Rear Panel Connectors). The Net-2000™ VCU
always outputs the audio to both the 4-Wire and Handset output regardless of which voice source is
selected.

APCO Vocoder Selection

The APCO Vocoder selection window allows the operator to select between the Full-Rate and Half-
Rate APCO Vocoders. Only one rate can be selected at a time. After switching from one rate to the
other it is necessary to select the start button in order to initiate the change.

Figure 8 Rate Selection

Full-Rate Vocoder Mode
The Full-Rate mode is compatible with the current APCO P25 Standard. The Full-Rate vocoder has
a total data bit rate of 7200 bps. Of these bits 4400 bps is voice data and 2800 bps is Forward Error
Correction (FEC).
DVSI Confidential Proprietary
Section 3 – Net-2000™ VCU Control
Page 11