Advertisement

Audio Aspects

  • Dag Åkerberg
  • Julian Trinder

Abstract

Cordless telephones use radio to provide the telephone user with the benefit of mobility. Conventionally, users of mobile radio have tolerated the poor speech quality often associated with an analogue radio channel. However, to today’s consumer the cordless telephone is viewed simply as another telephone and the same high speech quality associated with the fixed telephone network is expected. This chapter on audio aspects considers the requirements for, and outlines the approaches adopted in, the provision of good speech quality. It addresses in particular the special requirements arising in a Private Automatic Branch Exchange (PABX) environment and/or over local, national and international Public Switched Telephone Networks (PSTNs) when one or both telephones use digital cordless rather than wired links.

Keywords

Mean Opinion Score Speech Quality Voice Signal Linear Predictive Code Pulse Code Modulation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    BM Oliver, JR Pierce and CE Shannon. “The philosophy of PCM”, Proceedings of the IRE, vol 36, pp 1324–1331, October 1948Google Scholar
  2. 2.
    B Smith, “Instantaneous companding of quantised signals”, Bell Svstem Technical Journal, pp 653–709, 1957Google Scholar
  3. 3.
    NS Jayant, “Digital coding of speech waveforms: PCM, DPCM and DM quantisers”, Proceedings of the IEE, vol 62, pp 611–632, May 1974CrossRefGoogle Scholar
  4. 4.
    RW Stroh, “Optimum and adaptive differential PCM”, PhD dissertation. Polytechnic Institute of Brooklyn, Farmingdale NY, USA, 1970Google Scholar
  5. 5.
    P Cummiskey, “Adaptive differential PCM for speech processing”, PhD dissertation, Newark College of Engineering, Newark NJ, USA, 1973Google Scholar
  6. 6.
    P Cummiskey, NS Jayant and JL Flanagan, “Adaptive quantisation in differential PCM coding of speech”, Bell System Technical Journal, pp 1105–1118, September 1973Google Scholar
  7. 7.
    CCITT, “32 kbits/s adaptive differential pulse code modulation (ADPCM)”, CCITT Red Book vol 3, fascicle III.3 — Rec. G.721, 1984Google Scholar
  8. 8.
    CCITT, “Pulse code modulation (PCM) for voice frequencies”, CCITT red book vol 3, fascicle III.3 — Rec. G.711, 1984Google Scholar
  9. 9.
    A Tomozawa and H Kaneko, “Companded delta modulation for telephone transmission”, IEEE Transactions on Communication Technology, vol COM-16, pp 149–157, February 1968CrossRefGoogle Scholar
  10. 10.
    JE Abate, “Linear and adaptive delta modulation”. Proceedings of the IEE, vol 55, pp 298–308, March 1967CrossRefGoogle Scholar
  11. 11.
    JD Maskell and AH Gray, “Linear prediction of speech”, Springer-Verlag, Berlin Heidelberg New York, 1976Google Scholar
  12. 12.
    OFTEL, “Provisional code of practice for the design of private telecommunication branch networks”, Office of Telecommunications, London, UK, December 1986Google Scholar
  13. 13.
    ETSI, GSM Recommendation 06.10, annex 1, table 2, 1989Google Scholar
  14. 14.
    UK Department of Trade and Industry, “Common air interface specification to be used for the interworking between cordless telephone apparatus including public access services”, MPT 1375, London, May 1989 (amended November 1989, February 1990)Google Scholar
  15. 15.
    Swedish Telecom, “Swedish telecom regulations on radio technical requirements on digital cordless telephones in the frequcncv band 862 to 864 MHz”, Swedish Telecom Code of Statutes TVTFS 1989: 103, 1989Google Scholar
  16. 16.
    Swedish Telecom Specification, “Technical telephone requirements for a digital cordless telephone”, 8211-A:130, 1989Google Scholar
  17. 17.
    ETSI RES-3, DECT reference document, RES 3(89) 42, 1989Google Scholar
  18. 18.
    CCITT, “General characteristics of international telephone connections and circuits”, CCITT Red Book, vol 3, fascicle III. 1 — Rec. G.101 — G.181, 1984-1985Google Scholar
  19. 19.
    ETSI, “Overall transmission plan aspects of a private branch network for voice connections with access to the public network”, ETS T/TE 10-05, 6th edn, European Telecommunications Standards Institute, BP52, F-06561, Valbonne. Cedex, FranceGoogle Scholar
  20. 20.
    CCITT, “The effect of delayed side tone on the overall sound quality of the telephone connection”, CCITT Com.XII-226, November 1987, CCITT, Place des Nations, CH-1211, Geneva 20, SwitzerlandGoogle Scholar
  21. 21.
    D Åkerberg, “On echo control when a BCT with T ms inherent one-way delay is connected via a satellite link”, report TY87:2017, Ericsson Radio Systems AB, S-16480, Stockholm, SwedenGoogle Scholar

Copyright information

© Springer-Verlag London Limited 1990

Authors and Affiliations

  • Dag Åkerberg
  • Julian Trinder

There are no affiliations available

Personalised recommendations