GB1521209A - Conference circuit for a pcm switching network - Google Patents

Conference circuit for a pcm switching network

Info

Publication number
GB1521209A
GB1521209A GB4767776A GB4767776A GB1521209A GB 1521209 A GB1521209 A GB 1521209A GB 4767776 A GB4767776 A GB 4767776A GB 4767776 A GB4767776 A GB 4767776A GB 1521209 A GB1521209 A GB 1521209A
Authority
GB
United Kingdom
Prior art keywords
codes
rows
circuit
linear
conference
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
GB4767776A
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 Standard Electric Corp
Original Assignee
International Standard Electric 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 Standard Electric Corp filed Critical International Standard Electric Corp
Publication of GB1521209A publication Critical patent/GB1521209A/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)
  • Time-Division Multiplex Systems (AREA)
  • Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)

Abstract

1521209 TDM conference circuits INTERNATIONAL STANDARD ELECTRIC CORP 16 Nov 1976 [20 Nov 1975] 47677/76 Heading H4K A conference circuit for a PCM network whose frame time T defines m time slots of duration t comprises a store 3 for the non-linearly coded speech samples (codes), an expander 4 for converting the non-linear codes into linear ones, a linear summing circuit 6 and a compressor 9. The store comprises a read/write memory of m rows divided into K groups of I consecutive rows (m = K.I), each group corresponding to a conference, the m rows of the memory being written at the rate of one row per time slot t. During each time slot, the I rows of a group, including the written row, are read successively, with the memory being addressed in the period t/I. Thus, during the time slot assigned to a given subscriber taking part in a conference, the following occur: (a) the coded speech sample of the subscriber is written into a dedicated row of one group of the memory; (b) all the codes present in the rows of that group are read out successively; (c) all codes, apart from the subscriber's own, are summed at 6 and; (d) the summed linear code is converted to non-linear form at 9 and transmitted to the subscriber. An attenuation/noise suppression circuit may be located between the circuit 2 and the input and output buffers 1 and 30, Fig. 7 (not shown). This circuit attenuates both the codes at the input of those subscribers who are not speaking, and also the added codes at the output of those subscribers who are speaking.
GB4767776A 1975-11-20 1976-11-16 Conference circuit for a pcm switching network Expired GB1521209A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7535467A FR2332663A1 (en) 1975-11-20 1975-11-20 CONFERENCE CIRCUIT FOR MIC SWITCHING NETWORK

Publications (1)

Publication Number Publication Date
GB1521209A true GB1521209A (en) 1978-08-16

Family

ID=9162663

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4767776A Expired GB1521209A (en) 1975-11-20 1976-11-16 Conference circuit for a pcm switching network

Country Status (6)

Country Link
BE (1) BE848460A (en)
BR (1) BR7607674A (en)
ES (1) ES453481A1 (en)
FR (1) FR2332663A1 (en)
GB (1) GB1521209A (en)
IT (1) IT1064278B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4408323A (en) 1981-06-29 1983-10-04 Bell Telephone Laboratories, Incorporated Processor facilities for integrated packet and voice switching
GB2128448A (en) * 1982-10-08 1984-04-26 Standard Telephones Cables Ltd Telephone exchange conference circuit
GB2134751A (en) * 1983-01-18 1984-08-15 Plessey Co Plc Conference bridge
USRE31651E (en) * 1977-10-12 1984-08-21 Bell Telephone Laboratories, Incorporated Communication system using intelligent network processor

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4112258A (en) * 1977-10-12 1978-09-05 Bell Telephone Laboratories, Incorporated Communication system using intelligent network processor
FR2472318B1 (en) * 1979-12-18 1986-07-18 Telecommunications Sa TELEPHONE CONFERENCE SYSTEM
CA1151327A (en) * 1981-06-08 1983-08-02 Ernst A. Munter Digital conference circuit and method
DE3148886C1 (en) * 1981-12-10 1983-08-11 Standard Elektrik Lorenz Ag, 7000 Stuttgart Method and circuit arrangement for establishing a conference connection
NL8201058A (en) * 1982-03-15 1983-10-03 Philips Nv METHOD AND APPARATUS FOR ESTABLISHING A CONFERENCE CONNECTION IN A TDM COMMUNICATION SYSTEM

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE31651E (en) * 1977-10-12 1984-08-21 Bell Telephone Laboratories, Incorporated Communication system using intelligent network processor
US4408323A (en) 1981-06-29 1983-10-04 Bell Telephone Laboratories, Incorporated Processor facilities for integrated packet and voice switching
GB2128448A (en) * 1982-10-08 1984-04-26 Standard Telephones Cables Ltd Telephone exchange conference circuit
US4566096A (en) * 1982-10-08 1986-01-21 Standard Telephones And Cables, Public Limited Company Telephone exchange conference circuit
GB2134751A (en) * 1983-01-18 1984-08-15 Plessey Co Plc Conference bridge

Also Published As

Publication number Publication date
IT1064278B (en) 1985-02-18
ES453481A1 (en) 1977-11-16
FR2332663B1 (en) 1979-07-27
FR2332663A1 (en) 1977-06-17
BE848460A (en) 1977-05-18
BR7607674A (en) 1977-10-04

Similar Documents

Publication Publication Date Title
US3681756A (en) System for frequency modification of speech and other audio signals
US4359603A (en) CVSD Multiple conference system
US4387457A (en) Digital conference circuit and method
ES407164A1 (en) Time division switching system
US4224688A (en) Digital conference circuit
GB1521209A (en) Conference circuit for a pcm switching network
US3971891A (en) Adaptable time division switch
US3984643A (en) Method and apparatus for establishing a plurality of simultaneous conferences in a PCM switching system
CA1189205A (en) Demultiplexer circuit
SE7604727L (en) PROCEDURE AND ARRANGEMENTS TO PROVIDE SEVERAL CONTEMPORARY CONFERENCES IN THE EVENT OF A TIME-DIVIDED SWITCH SYSTEM
GB1458032A (en) Conference circuits for use in telecommunications systems
GB1182363A (en) Subscriber Subset for PCM Telephone System
US4975902A (en) Circuit for putting in conference a plurality of participants in telecommunication systems
US3050589A (en) Multiplex signaling system
US4479212A (en) Conference circuit
ES398554A1 (en) Pcm telecommunication system with tdma voice transmission
GB1498316A (en) Multiple connection device for a digital tdm switching centre
US4495616A (en) PCM Conference circuit
US3426158A (en) Remote switch unit in a common control telephone system
EP0067006B1 (en) Digital conference circuit and method
ES475186A1 (en) Time division multiplex telephone exchange
USRE29991E (en) Adaptable time division switch
ES453929A1 (en) A circuit for conference for a mic shuttering mesh. (Machine-translation by Google Translate, not legally binding)
ES8500690A1 (en) Circuit arrangement for composing and separating speech and data during the transmission in a digital switching network.
BE902364A (en) METHOD FOR PROCESSING MODEM SIGNALS.

Legal Events

Date Code Title Description
PS Patent sealed
746 Register noted 'licences of right' (sect. 46/1977)
PCNP Patent ceased through non-payment of renewal fee