US1974090A - Multiplex signaling system - Google Patents

Multiplex signaling system Download PDF

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Publication number
US1974090A
US1974090A US673842A US67384233A US1974090A US 1974090 A US1974090 A US 1974090A US 673842 A US673842 A US 673842A US 67384233 A US67384233 A US 67384233A US 1974090 A US1974090 A US 1974090A
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US
United States
Prior art keywords
lines
carrier
cable
voice
circuits
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 - Lifetime
Application number
US673842A
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English (en)
Inventor
Ira G Wilson
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.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
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
Priority to NL38792D priority Critical patent/NL38792C/xx
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US673842A priority patent/US1974090A/en
Priority to GB11803/34A priority patent/GB436870A/en
Priority to DEI49656D priority patent/DE682065C/de
Priority to FR773796D priority patent/FR773796A/fr
Application granted granted Critical
Publication of US1974090A publication Critical patent/US1974090A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems

Definitions

  • This invention relates to two-way signaling over a multiplicity of circuits such as those comprised in a'tel'ephone cable, although in its broadestaspects the invention is not limited to 5 telephony.
  • An object of the invention is to increase the message-carrying capacity of a cable or other group of transmission lines or circuits.
  • This object is accomplished according to the present invention by multiplexing only certain of the lines of the cable for carrier transmission and pairing the message channelsthus formed with individual lines that are not multiplexed.
  • a schematic circuit diagram of a cable system l5 embodying the invention is given in the single figure of the accompanying drawing.
  • the cable is indicated by showing its two ends at 1, 1 the central portion through the major extent of its length being 120 broken away in the diagram.
  • Long cables of the prior art have generally consisted of voice frequency circuits operated on a four-wire basis and loaded. That is, half the circuits transmitted east and the other half transmitted west. Each line contained one-way repeaters. A complete two-way voice circuit was made up by associating as a two-way pair one one-way line with another transmitting in the opposite direction. Subscribers loops or other two-wire lines were then connected to the pair of one-way lines at each terminal by means of hybrid repeating coils. This gave half as many two-way conversational circuits as there were pairs in the cable.
  • the invention provides an economical way of applying multiplex carrier to a cable of ordinary construction to increase the message-carrying capacity. This is done by multiplexing certain of the lines, shown at 10, 20 in the drawing, so
  • the cross-talk requirements may be 50 brought within practicable limits without resorting to the use of separate cables or shields within the cable as might be necessary where oppositely directed lines were included within the cable and used the same frequency ranges.
  • the carrier line 10 is associated with m subscribers lines L1, L2 to Lm by means of suitable carrier terminal apparatus such as modulators, 30, 31 etc. and band filters 40, 41 etc. in accordance with standard practice for carrier transmission.
  • Each line L1, L2 etc. has a hybrid coil H and line balancing network N for associating the line with the carrier modulating circuit for transmitting and with the return voice line 11 or 12 etc. for receiving.
  • a similar arrangement is illustrated for associating the m lines L11, L12 to Llm with the carrier line 20 for transmitting eastward and with the m individual voice lines 13, 14 etc. for receiving in the westward direction.
  • Mid-line repeaters are shown in the carrier lines at RE and in the voice lines at RW.
  • the carrier lines at RE On account of the higher attenuation in the cara rier range it may be necessary to use closer repeater spacing in the carrier lines than in the voice lines and this is indicated in the drawing by the two carrier repeater points RE, RE for the one repeater point RW in the voice lines.
  • the invention has application to many different situations in practice. Two such situations will be described.
  • all 10 non-loaded lines will be multiplexed to provide9 channels each or a total of 9G eastward channels to go with the 90 Westward voice lines.
  • the carrier lines may use the range of 4 to 40 KC or any other suitable range for the 9 channels assumed.
  • the carrier repeaters may be of the type disclosed in an application of H. S. Black, Serial N0. 606,871, filed April 22, 1932;
  • the carrier lines are preferably spaced apart' withinthe cable so that a number of low frequency pairs intervene between carrier lines and provide some shielding against cross-talk between the carrier lines.
  • Atwo-way signaling system comprising a cable consisting of a plurality of lines multiplexed for carrier transmission in the same direction to provide a plurality of channels per line, and a number of low frequency simplex one-way lines equal in number to the total number of the carrier channels, and all transmitting in the oppositedirection with respect to said carrier channels, and two-way terminal circuits cooperating with said carrier and low frequency lines, each such two-way terminal circuit being connected for eastward transmission over a respective carrier channel and for westward transmission over a respective lowfrequency line.
  • a two-Way telephone system comprising a cable consisting of n non-loaded lines multiplexed for carrier operation to provide m carrieij telephone channels per line all directed the same way and utilizing the same over-all carrier frequency range, and n.m one-way loaded voice circuits for transmission in the opposite direction, and terminal circuit connections for utilizing each carrier channel as one side of a four-wire conversational circuit and one of said voice lines for the opposite side of the respective

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
US673842A 1933-06-01 1933-06-01 Multiplex signaling system Expired - Lifetime US1974090A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL38792D NL38792C (fr) 1933-06-01
US673842A US1974090A (en) 1933-06-01 1933-06-01 Multiplex signaling system
GB11803/34A GB436870A (en) 1933-06-01 1934-04-19 High frequency signalling systems
DEI49656D DE682065C (de) 1933-06-01 1934-05-09 Anordnung zur nachtraeglichen Erhoehung der Zahl der Sprechwege bei bereits im Gebrauch befindlichen Kabelanlagen
FR773796D FR773796A (fr) 1933-06-01 1934-05-29 Perfectionnements aux systèmes de signalisation à hautes fréquences

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US673842A US1974090A (en) 1933-06-01 1933-06-01 Multiplex signaling system

Publications (1)

Publication Number Publication Date
US1974090A true US1974090A (en) 1934-09-18

Family

ID=24704315

Family Applications (1)

Application Number Title Priority Date Filing Date
US673842A Expired - Lifetime US1974090A (en) 1933-06-01 1933-06-01 Multiplex signaling system

Country Status (5)

Country Link
US (1) US1974090A (fr)
DE (1) DE682065C (fr)
FR (1) FR773796A (fr)
GB (1) GB436870A (fr)
NL (1) NL38792C (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3383464A (en) * 1962-11-29 1968-05-14 Siemens Ag Teleprinter system with plural forward channels and common time-division-multiplexedreturn channel

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3383464A (en) * 1962-11-29 1968-05-14 Siemens Ag Teleprinter system with plural forward channels and common time-division-multiplexedreturn channel

Also Published As

Publication number Publication date
GB436870A (en) 1935-10-21
DE682065C (de) 1939-10-07
NL38792C (fr)
FR773796A (fr) 1934-11-26

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