GB1031448A - Improvements in or relating to line-testing systems for telecommunications systems - Google Patents

Abstract

1,031,448. Supervising unattended repeaters. SIEMENS & HALSKE A.G. Sept. 7, 1964 [Sept. 6, 1963], No. 36574/64. Heading H4R. [Also in Divisions G1 and G4] In a transmission system having separate lines for go and return paths in which the lines are interconnected by a series of couplings at a series of mutually spaced positions along the lines, e.g. at unattended repeater positions, and a pulse applied to the go line at a terminal station is passed to the return line through each of the couplings and received back at the terminal station as a series of pulses spaced by the transit time of the pulses from one coupling to the next, a transmission property of each coupling is variable in response to a fault criterion in a section of the line adjacent to that coupling. Preferably the pulses applied to the line for fault-finding occupy a frequency band adjacent to that used for the information transmission, the repeaters passing both bands, and the coupling networks, which are coupled to the lines by high impedance networks, include band-pass filters passing only the band occupied by the test pulses. The transmission property of the coupling, e.g. the attenuation, may be varied to indicate faults in the repeater itself or in the line. For example, by a manometric pressure dependent contact across the input or output of the coupling network a leak in the cable may be located. In such an arrangement the operation of the contact may be arranged to send a signal, common to all repeaters, to initiate the pulse-testing arrangement.