The Analog Termination

  • John C. McDonald
Part of the Applications of Communications Theory book series (ACTH)


Public and private networks will evolve into all-digital facilities, and one day the analog interface will be exclusively located on the customer’s premises. Until that time, we will continue to live in a world that is a mixture of analog and digital. A new digital switch must have suitable analog terminations that are directly compatible with the existing analog telephone plant. In public applications, the digital switch cannot exclusively require digital telephones because customers often own their own instruments, which are analog. In any case, it would be very difficult and costly to introduce a new type of telephone at the time of a large switching system cutover. In private network applications, there is more flexibility in introducing digital telephones. However, the private digital switch usually will have suitable analog terminations for trunks.


Analog Termination Vocal Tract Code Word Switching System Pulse Code Modulation 
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  1. 1.
    N. J. Skaperda, “Some Architectural Alternatives in the Design of a Digital Switch,” IEEE Trans. Commun., vol. COM-27 (7), p. 961, July 1979.Google Scholar
  2. 2.
    A. F. Bennett, “An Improved Circuit for the Telephone Set,” Bell Syst. Tech. J., vol. 32, May 1953.Google Scholar
  3. 3.
    Bell Telephone Laboratories, Inc., Transmission Systems for Communications, Chap. 3, 1970.Google Scholar
  4. 4.
    J. C. McDonald, “Techniques for Digital Switching, IEEE Commun. Mag., July, 1978.Google Scholar
  5. 5.
    R. L. Bunker, F. J. Scida, and R. P. McCabe, “Line Matching Networks to Support Zero Loss Operation in Digital Class 5 Offices,” Intl. Symp. on Subscriber Loops and Services Record, 1978.Google Scholar
  6. 6.
    J. L. Neigh, “Transmission Planning for an Evolving Local Switched Digital Nework,” IEEE Trans. Commun., vol. COM 27, July, 1979.Google Scholar
  7. 7.
    United States Department of Agricultural Rural Electrification Administration, “General Specification for Digital, Stored Program Controlled Central Office Equipment,” June 1978.Google Scholar
  8. 8.
    M. N. Evans, “Telephone Company Planning for the Integration of Electronics in the Local Network,” Intl. Symp. on Subscriber Loops and Services Record, 1976.Google Scholar
  9. 9.
    J. O. Bergholm, J. G. Eckert, and P. A. Gresh, “Evolving Designs for Bell System Urban-Suburban Loop Plant,” Intl. Symp. on Subscriber Loops and Services Record, 1974.Google Scholar
  10. 10.
    S. Okubo et al., “Progress of CCITT Standardization on n x 384 kbit/s Video Codec,” Conf. Record, Globecom ’87, pp. 36–39, November 1987.Google Scholar
  11. 11.
    R. V. Cox et al., “Real-time Implementation of Time Domain Harmonic Scaling of Speech for Rate Modification and Coding,” IEEE Trans., ASSP-31, pp. 258–272, 1983.Google Scholar
  12. 12.
    J. Chen and A. Gersho, “Real-Time Vector APC Special Coding at 4800 bps with Adaptation Post-filtering,” Proc. ICASSP, pp. 51–53, April 1987.Google Scholar
  13. 13.
    N. Jayant and P. Noll, Digital Coding of Waveforms, Prentice-Hall, Englewood Cliffs, N.J., 1985.Google Scholar
  14. 14.
    CCITT Recommendation G.722 for 64 kbit/s PCM.Google Scholar
  15. 15.
    J. L. Flanagan, M. R. Schroeder, B. S. Atal, R. E. Crochiere, N. S. Jayant, and J. M. Tribolet, “Speech Coding,” IEEE Trans. Commun., vol. COM-27, April 1979.Google Scholar
  16. 16.
    CCITT, Recommendation Series G700, Geneva, 1972.Google Scholar
  17. 17.
    Recommendation G.721 32 kbit/s Adaptive Differential Pulse Code Modulation CCITT 1984.Google Scholar
  18. 18.
    P. Fritz, “Citedis Production PCM, Public Telephone Switching System,” IEEE Trans. Commun., September, 1974.Google Scholar
  19. 19.
    F. T. Andrews, Jr. and W. B. Smith, “No. 5 ESS-Overview,” Intl. Switching Symp., September, 1981.Google Scholar
  20. 20.
    H. Sueyoshi, N. Shimasaki, A. Kitamura, and T. Yamaguchi, “System Design of Digital Telephone Switching System-NEAX 61,” IEEE Trans. Commun., vol. COM-27, July, 1979.Google Scholar
  21. 21.
    N. J. Skaperda, “Generic Digital Switching System,” Intl. Switching Symp., October, 1976.Google Scholar
  22. 22.
    K. Galpin et al., “Progress in Analogue Line Card LSI Circuits in Europe,” Conf. Record Int. Switching Symp., pp. C. 7.2.1-C. 7.2.5., 1987.Google Scholar
  23. 23.
    P. Chea et al., “System 12 Line Circuit Technology,” Conf. Proc. Int. Switching Symp., May 1984.Google Scholar
  24. 24.
    J. Ames, “Line Interfacing-Its Status and Evolution,” Conf. Proc. Int. Switching Symp., May 1984.Google Scholar
  25. 25.
    V. K. Korsky, “Telephone Line Circuit with Differential Loop Current Sensing and Compensation,” U.S. Patent 4, 103, 112.Google Scholar
  26. 26.
    H. Mussman et al., “Design Techniques Which Reduce the Size and Power of the Subscriber Interface to a Local Exchange,” Zurich Conference on Digital Communications, 1978.Google Scholar
  27. 27.
    J. R. Sergo, “DSS Quad Line Circuit,” Intl. Symp. on Subscriber Loops and Services, 1978.Google Scholar
  28. 28.
    N. Mokhoff, “Communication ICs,” IEEE Spectrum, January, 1982.Google Scholar
  29. 29.
    T. Kozaki et al., “Autobalancing Network Using Digital Signal Processing,” Conf. Record, Globecom ’87, pp. 1366–1370, November 1987.Google Scholar
  30. 30.
    J. L. Neigh, “Transmission Planning for an Evolving Local Switched Digital Network,” IEEE Trans. Commun., vol. COM-27, July 1979.Google Scholar
  31. 31.
    D. G. Messerschmitt, “An Electronic Hybrid with Adaptive Balancing for Telephony,” IEEE Trans. Commun., vol. COM-28, August 1980.Google Scholar
  32. 32.
    Y. P. Tsividis, P. R. Gray, D. Hodges and J. Chacko, Jr. “A Segmented y-255 Law PCM Voice Encoder Utilizing NMOS Technology,” IEEE J. Solid-State Circuits, December, 1976.Google Scholar
  33. 33.
    Y. Tomita et al., “An Implementation of the 64 kbps Audio Codec Based on CCITT Recommendation G.722,” Conf. Record, Globecom ’87, pp. 463–476, November 1987.Google Scholar
  34. 34.
    T. Kimura et al., “A Dual-Chip SLIC Using VLSI Technology,” Conf. Record, Globecom ’87, pp. 1766–1770, November 1987.Google Scholar

Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • John C. McDonald
    • 1
  1. 1.Contel CorporationNew YorkUSA

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