12 Performance with signalling tones

3GPP46.008Half rate speechPerformance Characterization of the GSM Half Rate speech codecRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

The capability of the codec to transmit network information tones was assessed with 5 French signalling tones following the IUT-T recommendation: "Warn" tone, "Busy" tone, "Ring" tone, "Inf" tone and "Pay" tone (tones of length 200 ms to 1s and silences between tones of length 30 ms to 4 s).

All signalling tones are recognized. However, the half rate codec introduces a very audible distortion and performs significantly worse than the full rate codec.

None of the tones is perturbed by the VAD/DTI system.