GB1381554A - Transmission systems - Google Patents

Transmission systems

Info

Publication number
GB1381554A
GB1381554A GB2469072A GB2469072A GB1381554A GB 1381554 A GB1381554 A GB 1381554A GB 2469072 A GB2469072 A GB 2469072A GB 2469072 A GB2469072 A GB 2469072A GB 1381554 A GB1381554 A GB 1381554A
Authority
GB
United Kingdom
Prior art keywords
pilot signal
multivibrator
signal
delay
enabled
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
GB2469072A
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.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB2469072A priority Critical patent/GB1381554A/en
Priority to ZA732618A priority patent/ZA732618B/en
Priority to AU55306/73A priority patent/AU478087B2/en
Priority to ES415180A priority patent/ES415180A1/en
Priority to FR7319082A priority patent/FR2185902B1/fr
Publication of GB1381554A publication Critical patent/GB1381554A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/40—Monitoring; Testing of relay systems
    • H04B17/401—Monitoring; Testing of relay systems with selective localization
    • H04B17/402—Monitoring; Testing of relay systems with selective localization using different frequencies
    • H04B17/403—Monitoring; Testing of relay systems with selective localization using different frequencies generated by local oscillators

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)

Abstract

1381554 Supervizing unattended repeaters STANDARD TELEPHONES & CABLES Ltd 25 May 1972 24690/72 Heading H4R A dependent repeater in a line transmission system provides a locally generated pilot signal when a failure of the transmitted pilot signal is detected. The system includes both regulated and unregulated repeaters and the latter are arranged to switch to a predetermined gain on detecting a failure of the pilot signal which could result in the received signals being outside the working range of the terminal station amplifier. To restore some control at least one dependent repeater with a circuit for monitoring the presence of the pilot signal and an oscillator for locally generating a pilot signal when necessary and a time discriminating arrangement for preventing the locally generated signal affecting the monitoring circuit. As shown, the local oscillator 21 can provide the pilot signal when enabled by output m 1 of multivibrator M. The pilot signal on the line is monitored by the circuit comprising filter F, amplifier A a rectifier R and when it is outside the operating range for a time longer than delay D (5-10 seconds) the multivibrator M is enabled. The multivibrator provides a signal at m 1 for 1. second and a signal at m 2 for 10 milliseconds so that the oscillator 21 operates for 1 sec. and following a delay of 2 msec. imposed by delay d the amplifier A is enabled for 8 msecs. and monitors the line for restoration of the transmitted pilot signal when the multivibrator is disabled. In typical line transmission systems different delay periods may be used depending on the location of the repeater. Additionally loopback can be provided to operate with further oscillators to give a fault location facility.
GB2469072A 1972-05-25 1972-05-25 Transmission systems Expired GB1381554A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
GB2469072A GB1381554A (en) 1972-05-25 1972-05-25 Transmission systems
ZA732618A ZA732618B (en) 1972-05-25 1973-04-17 Improvements in or relating to transmission systems
AU55306/73A AU478087B2 (en) 1972-05-25 1973-05-07 Improvements in and relating to transmission systems
ES415180A ES415180A1 (en) 1972-05-25 1973-05-25 Transmission systems
FR7319082A FR2185902B1 (en) 1972-05-25 1973-05-25

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2469072A GB1381554A (en) 1972-05-25 1972-05-25 Transmission systems

Publications (1)

Publication Number Publication Date
GB1381554A true GB1381554A (en) 1975-01-22

Family

ID=10215740

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2469072A Expired GB1381554A (en) 1972-05-25 1972-05-25 Transmission systems

Country Status (4)

Country Link
ES (1) ES415180A1 (en)
FR (1) FR2185902B1 (en)
GB (1) GB1381554A (en)
ZA (1) ZA732618B (en)

Also Published As

Publication number Publication date
FR2185902A1 (en) 1974-01-04
ZA732618B (en) 1974-04-24
AU5530673A (en) 1974-11-07
FR2185902B1 (en) 1978-01-06
ES415180A1 (en) 1976-02-01

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Legal Events

Date Code Title Description
PS Patent sealed
435 Patent endorsed 'licences of right' on the date specified (sect. 35/1949)
PCNP Patent ceased through non-payment of renewal fee