BEGIN:VCALENDAR
VERSION:2.0
PRODID:IEEE vTools.Events//EN
CALSCALE:GREGORIAN
BEGIN:VTIMEZONE
TZID:Mexico/General
BEGIN:STANDARD
DTSTART:20221030T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0600
TZNAME:CST
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20251025T180337Z
UID:8ED82315-84E2-4F24-B0B9-3739C9D3609B
DTSTART;TZID=Mexico/General:20251021T130000
DTEND;TZID=Mexico/General:20251021T140000
DESCRIPTION:Voiceband modems convert a stream of digital symbols into audib
 le signals and transmit them over the Public Switched Telephone Network (P
 STN). The first voiceband modem was developed in 1958 and operated at 110 
 bits/s. Being subject to international standards developed by the Internat
 ional Union of Telecommunications\, Telecommunication Standardization Sect
 or (ITU-T)\, a body of the United Nations\, these modems consistently incr
 eased their transmission speeds within the next several decades. Every ste
 p in the standards process involved a major development in signal processi
 ng and communications\, such as various forms of adaptive equalization\, e
 cho cancellation\, and trellis coded modulation. These contributions appro
 ximately doubled the transmission speed every step of the standardization 
 process\, starting with 300 b/s in 1962 until about 28.8-33.6 kb/s in 1996
 . Modem designers invoked Shannon's capacity formula and considering quant
 ization noise occurring at the Analog-to-Digital conversion process in the
  PSTN Central Office as additive white Gaussian noise\, decided that the c
 hannel capacity for such modems is about 36 kb/s. Yet\, towards the end of
  1990s\, modems that operated at transmission speeds close to 56 kb/s\, kn
 own generally as 56K modems appeared. This talk will first give a brief hi
 story of voiceband modems\, and it will describe how it was possible to be
 at the Shannon capacity formula with the 56K modems. The underlying modeli
 ng process and the related mathematics will be described. A history of the
  development of the 56K modems will be presented and\, looking back severa
 l decades\, the technological\, as well as the economic and social impact 
 of these modems\, will be discussed.\n\nCo-sponsored by: Benemérita Unive
 rsidad Autónoma de Puebla\n\nSpeaker(s): Ender Ayanoglu\n\nRoom: Auditori
 o Facultad Ciencias de la Electrónica\, Bldg: Edificio FCE2 - 101 \, Bene
 mérita Universidad Autónoma de Puebla\, Av. San Claudio y 18 sur\; Ciuda
 d Universitaria\, Puebla\, Puebla\, Mexico\, 72592\, Virtual: https://even
 ts.vtools.ieee.org/m/497705
LOCATION:Room: Auditorio Facultad Ciencias de la Electrónica\, Bldg: Edifi
 cio FCE2 - 101 \, Benemérita Universidad Autónoma de Puebla\, Av. San Cl
 audio y 18 sur\; Ciudad Universitaria\, Puebla\, Puebla\, Mexico\, 72592\,
  Virtual: https://events.vtools.ieee.org/m/497705
ORGANIZER:jvazquezbu@hotmail.com
SEQUENCE:32
SUMMARY:Beating the Shannon Limit in Voiceband Modems. The Case of the 56K 
 Modem
URL;VALUE=URI:https://events.vtools.ieee.org/m/497705
X-ALT-DESC:Description: <br /><p class="MsoNormal"><span lang="EN-US" style
 ="font-size: 11.0pt\; mso-bidi-font-size: 10.0pt\; font-family: 'Verdana'\
 ,sans-serif\; color: #131313\;">Voiceband modems convert a stream of digit
 al symbols into audible signals and transmit them over the Public Switched
  Telephone Network (PSTN). The first voiceband modem was developed in 1958
  and operated at 110 bits/s. Being subject to international standards deve
 loped by the International Union of Telecommunications\, Telecommunication
  Standardization Sector (ITU-T)\, a body of the United Nations\, these mod
 ems consistently increased their transmission speeds within the next sever
 al decades. Every step in the standards process involved a major developme
 nt in signal processing and communications\, such as various forms of adap
 tive equalization\, echo cancellation\, and trellis coded modulation. Thes
 e contributions approximately doubled the transmission speed every step of
  the standardization process\, starting with 300 b/s in 1962 until about 2
 8.8-33.6 kb/s in 1996. Modem designers invoked Shannon's capacity formula 
 and considering quantization noise occurring at the Analog-to-Digital conv
 ersion process in the PSTN Central Office as additive white Gaussian noise
 \, decided that the channel capacity for such modems is about 36 kb/s. Yet
 \, towards the end of 1990s\, modems that operated at transmission speeds 
 close to 56 kb/s\, known generally as 56K modems appeared. This talk will 
 first give a brief history of voiceband modems\, and it will describe how 
 it was possible to beat the Shannon capacity formula with the 56K modems. 
 The underlying modeling process and the related mathematics will be descri
 bed. A history of the development of the 56K modems will be </span><span s
 tyle="color: rgb(19\, 19\, 19)\; font-family: Verdana\, sans-serif\; font-
 size: 11pt\;">presented and\, looking back several decades\, the technolog
 ical\, as well as the economic and social impact of these modems\, will be
  discussed.</span></p>
END:VEVENT
END:VCALENDAR