GB1499179A - Conference call circuitry for tdm signal exchange - Google Patents

Conference call circuitry for tdm signal exchange

Info

Publication number
GB1499179A
GB1499179A GB17151/75A GB1715175A GB1499179A GB 1499179 A GB1499179 A GB 1499179A GB 17151/75 A GB17151/75 A GB 17151/75A GB 1715175 A GB1715175 A GB 1715175A GB 1499179 A GB1499179 A GB 1499179A
Authority
GB
United Kingdom
Prior art keywords
circuit
pass filter
speech
filter
low
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB17151/75A
Other languages
English (en)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of GB1499179A publication Critical patent/GB1499179A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/42—Systems providing special services or facilities to subscribers
    • H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities
    • H04M3/561—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities by multiplexing

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
  • Interface Circuits In Exchanges (AREA)
GB17151/75A 1974-06-03 1975-04-25 Conference call circuitry for tdm signal exchange Expired GB1499179A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/475,681 US3983332A (en) 1974-06-03 1974-06-03 Conference call circuitry for TDM signal exchange

Publications (1)

Publication Number Publication Date
GB1499179A true GB1499179A (en) 1978-01-25

Family

ID=23888645

Family Applications (1)

Application Number Title Priority Date Filing Date
GB17151/75A Expired GB1499179A (en) 1974-06-03 1975-04-25 Conference call circuitry for tdm signal exchange

Country Status (7)

Country Link
US (1) US3983332A (https=)
JP (1) JPS5748912B2 (https=)
CA (1) CA1035450A (https=)
DE (1) DE2517977C2 (https=)
FR (1) FR2273424B1 (https=)
GB (1) GB1499179A (https=)
IT (1) IT1038271B (https=)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5940341B2 (ja) * 1977-06-29 1984-09-29 株式会社東芝 時分割交換会議システム
JPS5457161A (en) * 1977-10-14 1979-05-08 Hitachi Ltd Preparation of doughnuttlike coil
IE47520B1 (en) * 1977-12-05 1984-04-04 Post Office Improvements in or relating to audio teleconferencing
WO1980002095A1 (en) * 1979-03-23 1980-10-02 Small World Exchange Inc Telephone-conferencing apparatus and method
US4305149A (en) * 1979-03-23 1981-12-08 Small World Exchange, Inc. Conferencing method and apparatus with multiplexed analog signals
US4311878A (en) * 1979-07-02 1982-01-19 Bell Telephone Laboratories, Incorporated Dialing interval transmission gating arrangement
FR2498403A1 (fr) * 1981-01-21 1982-07-23 Telephonie Ind Commerciale Procede et dispositif de melange de signaux basse frequence transmis par des voies temporelles differentes vers un meme organe telephonique recepteur
SE449152B (sv) * 1986-03-19 1987-04-06 Paul Gosta Wilhelm Rosen Kommunikationsanleggning innefattande ett flertal enheter vilka kan uppretthalla en konferenskoppling

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3293369A (en) * 1963-12-20 1966-12-20 Ibm Conference communications system employing time division multiplex
US3551600A (en) * 1968-02-23 1970-12-29 Stromberg Carlson Corp High capacity,high side-tone suppression,4-wire conference circuit
US3692947A (en) * 1970-12-21 1972-09-19 Bell Telephone Labor Inc Time division switching system conference circuit
US3699264A (en) * 1971-03-02 1972-10-17 Gte Automatic Electric Lab Inc Conference circuit for pulse code modulated telephony
US3835259A (en) * 1973-03-22 1974-09-10 Bell Telephone Labor Inc Time division conference hybrid circuit
US3870819A (en) * 1973-12-26 1975-03-11 Roderick A Dennis Conference call apparatus for use with key telephone system equipment

Also Published As

Publication number Publication date
FR2273424A1 (https=) 1975-12-26
FR2273424B1 (https=) 1977-04-15
JPS511014A (https=) 1976-01-07
USB475681I5 (https=) 1976-01-20
US3983332A (en) 1976-09-28
DE2517977C2 (de) 1983-08-18
CA1035450A (en) 1978-07-25
DE2517977A1 (de) 1975-12-18
IT1038271B (it) 1979-11-20
JPS5748912B2 (https=) 1982-10-19

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee