- Tone detection:
Eight channels are available for tone detection. The different paces are validated by the
firmware coupler, levels and frequencies are validated by the DSP software.
- External tone detection on the NDDI2-2 interfaces:
There are two types of tone:
• Dial tone,
• Busy tone.
- Ringing detection:
Eight ringing detection channels are necessary on the NDDI2-2 board. The different paces
are validated by the firmware coupler, levels and frequencies are validated by the DSP
software. The detector must handle frequencies ranging from 14.5 to 68 Hz.
- TAMIS Terminal equipment Alert Signaling (TAS) detection:
Eight TAS detection channels are necessary on the NDDI2-2 board. The TAS can be :
• Dual Tone Alert Signalling (DT-AS),
• Ringing Pulse Alert Signalling (RP-AS).
- Frequency Shift Keying (FSK) demodulation:
Eight FSK demodulation channels are necessary on the NDDI2-2 board (eight FSK carrier
detections are provided). FSK has the following features:
• bit duration: 833 µs,
• 0 logical frequency: 2200 ± 22 Hz (Bellecore) or 2100 ± 16 Hz (ETSI),
• 1 logical frequency: 1200 ± 12 Hz (Bellecore) or 1300 ± 16 Hz (ETSI),
• Signal level reception: -12 to 32.5 dBm (Bellecore) or -11 to -35 dBm (ETSI).
- Dual Tone Multi-Frequency (DTMF) detection:
In some countries, the messages can be transmitted using the 16 DTMF codes.
1.3.4 Common part
The common part is the interface between the NDDI2-2 board and the other ACT boards.
The Revision Code Number (RCN) register of the QLSLAC recognizes the NDDI2-2 board.
The MIC 0 link rated at 2.048 MHz transmits voice for 8 NDDI2-2 lines.
For more information on the common part, see Common Part - Common part.
1.3.5 Power supply
From -48V power supply, the CM8 converter supplies the NDDI2-2 board with +5V, -5V and
+12V.
3.3V regulators supply the QLSLAC and the DSP module.
#$!%$! &!'()'*
! " #$!%$! &!'()'*
1-5
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