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Quality VoIP — An Engineering Challenge

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BT Technology Journal

Abstract

Initial impressions of VoIP quality have not always been favourable. This paper discusses the issues behind delivering an 'appropriate' quality of service, specifically voice quality, by showing how design choices ultimately affect, and potentially limit, a customer's perception of VoIP quality.

The paper continues by introducing new signal processing techniques that are helping to measure and optimise the performance of VoIP solutions.

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References

  1. ITU-T Recommendation G. 114: ‘One-way transmission time’, (February 1996).

  2. ITU-T Recommendation G.102: ‘Transmission performance objectives and Recommendations’, (November 1988).

  3. ITU-T Recommendation G.131: ‘Control of talker echo’, (August 1996).

  4. ITU-T Recommendation G.168: ‘Digital network echo cancellers’, (March 2000).

  5. ETSI TIPHON: ‘End-to-end Quality of Service in TIPHON Systems; Part 2: Definition of Quality of Service (Qos) Classes’, TS 101 329-2, (July 2000).

  6. ITU-T Recommendation G.711: ‘Pulse code modulation (PCM) of voice frequencies’, (November 1988).

  7. ITU-T Recommendation G.726: ‘40, 32, 24, 16 kbit/s adaptive differential pulse code modulation (ADPCM)’, (December 1990).

  8. ITU-T Recommendation G.728: ‘Coding of speech at 16 kbit/s using low-delay code excited linear prediction’, (February 1992).

  9. ITU-Recommendation G.729: ‘C source code and test vectors for implementation verification of the G.729 8 kbit/s CS-ACELP speech coder’, (March 1996).

  10. ITU-T Recommendation G.723.1: ‘Dual rate speech coder for multimedia communications transmitting at 5.3 and 6. 3 kbit/s’, (March 1996).

  11. ETSI GSM, ETS 300 961: ‘Digital cellular telecommunications system (Phase 2+); Full rate speech; Transcoding (GSM 06. 10)’, (2000).

  12. ETSI GSM, ETS 300 726: ‘Digital cellular telecommunications system; enhanced full rate (EFR) speech transcoding (GSM 06. 60)’, (1999).

  13. Rix A W and Hollier M P: ‘The perceptual analysis measurement system for robust end-to-end speech quality assessment’, IEEE ICASSP (June 2000).

  14. Schulzrinne H et al: ‘RTP: a transport protocol for real-time applications’, IETF RFC 1889 (1996).

  15. Degermark M: ‘Requirements for robust IP/UDP/RTP header compression’, IETF Internet Draft (December 2000).

  16. Garner P et al: ‘Robust noise detection for speech detection and enhancement’, IEE Electronics Letters, 33, No 4, p 270-271, (February 1997).

    Google Scholar 

  17. Rix A W et al: ‘Perceptual measurement of end-to-end speech quality over audio and packet-based networks’, Audio Engineering Society 106th Convention, Pre-print No. 4873, (May 1999).

  18. ITU-T Recommendation P.562: ‘Analysis and interpretation of INMD voice-services measurements’, (May 2000).

  19. ITU-T Recommendation P.56: ‘Objective measurement of active speech level’, (March 1993).

  20. ITU-T Recommendation P.800: ‘Methods for subjective determination of transmission quality’, (August 1996).

  21. -T Recommendation P.861: ‘Objective quality measurement of telephone band (300-3400 Hz) speech codecs’, (August 1996).

  22. -T Recommendation P.862: ‘Perceptual evaluation of speech quality (PESQ), an objective method for end-to-end speech quality assessment of narrowband telephone networks and speech codecs’, (February 2001).

  23. -T Recommendation P.561: ‘In-service, non-intrusive measurement device-voice service measurements’, (February 1996).

  24. ETSI ETR 250: ‘Transmission and multiplexing (TM); Speech communication quality from mouth to ear for 3. 1 kHz handset telephony across networks’, (July 1996).

  25. Gray P et al: ‘Non-Intrusive speech-quality assessment using vocaltract models’, IEE Proceedings-Vision, Image and Signal Processing, 147, No 6, pp 493-501, (December 2000).

    Google Scholar 

  26. -T Recommendation P.48: ‘Specification for an Intermediate Reference System’, (November 1988).

  27. -T Recommendation P.830: ‘Subjective performance assessment of telephone-band and wideband digital codecs’, (August 1996)

  28. ETSI TIPHON: ‘Technology compliance specification; part 5: quality 28 service (QoS) measurement methodologies’, TS 101-329-5 (November 2000).

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Reynolds, R.J.B., Rix, A.W. Quality VoIP — An Engineering Challenge. BT Technology Journal 19, 23–32 (2001). https://doi.org/10.1023/A:1011382801542

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  • DOI: https://doi.org/10.1023/A:1011382801542

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