V.92: The Final Chapter in the Never-Ending Story of Dial-up Modems

  • D.-Y. Kim
  • P. A. Humblet
  • M. V. Eyuboglu
  • L. Brown
  • G. D. ForneyJr.
  • S. Mehrabanzad
Part of the The Kluwer International Series in Engineering and Computer Science book series (SECS, volume 670)


Ever since the first dial-up modems appeared in 1960s, many have repeatedly predicted their obsolescence. However, contrary to such predictions, dial-up modems actually thrived in the 80’s and 90’s as a result of slow roll-out of residential digital services, and the unprecented growth of Internet and remote access.

Since the first 300 b/s dial-up modem V.21, modem speeds increased steadily, most recently approaching download speeds of 56 kb/s in ITU Recommendation V.90, finalized in 1998. V.90 takes advantage of the direct-digital PCM network connection of an Internet Service Provider’s remote access server, to achieve such high downstream (from ISP to a user) speeds. However, for upstream transmission (from a user to ISP), V.90 employs the older V.34 technology which typically delivers 28.8 kb/s.

A new ITU modem standard called V.92 will increase upstream rates to above 40 kb/s, again taking advantage of PCM connections. In this paper, we present a new transmission scheme which is adopted in V.92. The proposed scheme is based on a generalization of Tomlinson-Harashima precoding.

As we predict that V.92 will be the last dial-up modem standard, we wonder whether we might be falling into the same trap that many others have fallen in the past. You can be the judge!


Equivalence Class Channel Code Data Symbol Constellation Point Base Constellation 
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Copyright information

© Springer Science+Business Media New York 2002

Authors and Affiliations

  • D.-Y. Kim
    • 1
  • P. A. Humblet
    • 2
  • M. V. Eyuboglu
    • 1
  • L. Brown
    • 3
  • G. D. ForneyJr.
    • 4
  • S. Mehrabanzad
    • 1
  1. 1.Airvana, Inc.USA
  2. 2.Institute EurecomFrance
  3. 3.ConexantUSA
  4. 4.MITCambridgeUSA

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