EP0047669A2
Expired / Lapsed
EP
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Telecommunication systems
Assignee: Balfour Beatty PLC
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Filing: 1981-09-08
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Granted: —
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Expires: 2001-09-08
Abstract
Abstract A simple two-way communication link by means of which data signals from a number of data inputs 17 at spaced positions along a highway 11 can be fed in individually in any desired sequence comprises a highway 11 constituted by an optical fibre; a gas laser 13 or other source of electromagnetic radiation of optical frequency at the end of the highway; a number of outstations 17 at spaced positions along the highway, each of which outstations comprises a modulator 18 for modulating a data signal onto a subcarrier which periodically varies the optical path lenght of a section of the highway with the modulated data signal, and has an associated receiver 20 for signals for controlling operation of the modulator; and, connected to the other end of the highway, a demodulator 16 and transmitter 21 for transmitting control signals to the receivers 20. Preferably the transmitter 21 and the receivers 20 are electrically interconnected by a pair of electric conductors constituting a leaky electric cable 12.
Inventors
- 👤 Alan Arthur Sadler
- 👤 Brian Culshaw
- 👤 Peter Raymond Ball
- 👤 John Charles Pond
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 07:42
CPC Classifications
H; H04; H04B; H04B10/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
117 words
A telecommunications system comprising a highway formed from an optical fibre; a source of coherent electromagnetic radiation of optical frequency, as hereinbefore defined, at one end of the highway; a plurality of outstations at spaced positions along the length of the highway, each of which outstations comprises means for modulating a data signal onto a sub-carrier and means for periodically varying the optical path length of a section of the highway < with the modulated data signal, and has an assocated receiver for signals for controlling operation of the modulating means or ancillary equipment; and, at the other end of the highway, demodulating means and means for transmitting control signals to the receivers associated with the outstations.
Claim 2
Dependent Claim
117 words
A telecommunications system comprising a highway formed from an optical fibre; a source of coherent electromagnetic radiation of optical frequency, as hereinbefore defined, at one end of the highway; a plurality of outstations at spaced positions along the length of the highway, each of which outstations comprises means for modulating a data signal onto a sub-carrier and means for periodically varying the optical path length of a section of the highway < with the modulated data signal, and has an assocated receiver for signals for controlling operation of the modulating means or ancillary equipment; and, at the other end of the highway, demodulating means and means for transmitting control signals to the receivers associated with the outstations.
Claim 3
Dependent Claim
139 words
A telecommunication system comprising a highway formed from an optical fibre; a source of coherent electromagnetic radiation of optical frequency, as hereinbefore defined, at one end of the highway; a plurality of outstations at spaced positions along the length of the highway, each of which outstations comprises means for modulating a data signal onto a sub-carrier and means for periodically varying the optical path length of a section of the highway with'the modulated data signal, and has an associated receiver for signals for controlling operation of the modulating means or ancillary equipment; demodulating means and means for transmitting control signals to the receivers associated with the outstations at the other end of the highway; and, electrically interconnecting the control signal transmitting means and the receivers associated with the outstations, a pair of electric conductors constituting a leaky electric cable.
Claim 4
Dependent Claim
139 words
A telecommunication system comprising a highway formed from an optical fibre; a source of coherent electromagnetic radiation of optical frequency, as hereinbefore defined, at one end of the highway; a plurality of outstations at spaced positions along the length of the highway, each of which outstations comprises means for modulating a data signal onto a sub-carrier and means for periodically varying the optical path length of a section of the highway with'the modulated data signal, and has an associated receiver for signals for controlling operation of the modulating means or ancillary equipment; demodulating means and means for transmitting control signals to the receivers associated with the outstations at the other end of the highway; and, electrically interconnecting the control signal transmitting means and the receivers associated with the outstations, a pair of electric conductors constituting a leaky electric cable.
Claim 5
Dependent Claim
24 words
A telecommunication system as claimed in Claim 2, wherein the optical fibre constituting the highway is a component element of the leaky electric cable.
Claim 6
Dependent Claim
61 words
A telecommunication system as claimed in Claim 3, wherein the leaky electric cable comprises an extruded elongate body of plastics insulating material having throughout its length a bore in which an optical fibre is loosely housed, and, embedded in the elongate body on opposite sides of and parallel to the bore, two strain wires of electrically conductive metal or metal alloy.
Claim 7
Dependent Claim
89 words
' 5. A telecommunication system as claimed in Claim 3, wherein the leaky electric cable comprises an extruded elongate body of plastics insulating material having throughout its length a bore in which an optical fibre is loosely housed, and, embedded in the elongate body on opposite sides of and parallel to the bore, a non-metallic elongate strain member and a pair of coaxial conductors, the outer conductor of which pair of coaxial conductors being of such a form that the pair of conductors constitutes a radiating or leaky cable.
Claim 8
Dependent Claim
70 words
A telecommunication system as claimed in Claim 4 or 5, wherein each modulating means takes the form of means for subjecting a length of the optical fibre forming the highway to periodic variations of stress in response to a modulating signal and wherein, at the positions of each outstation, the cable is so bent or flexed that the optical fibre is in direct contact with the wall of the bore.
Claim 9
Dependent Claim
75 words
A telecommunication system as claimed in Claim 4 or 5, wherein each modulating means takes the form of means for subjecting a length of the optical fibre forming the highway to periodic variations of stress in response to a modulating signal and wherein, throughout the length of the cable, the space in the bore not occupied by the optical fibre is filled with petroleum jelly or other material of a jelly- or grease- like nature.
Claim 10
Dependent Claim
44 words
A telecommunication system as claimed in any one of Claim 1 to 3, wherein each modulating means takes the form of means for subjecting a length of the optical fibre forming the highway to periodic variations of stress in response to a modulating signal.
Claim 11
Dependent Claim
42 words
A telecommunication system as claimed in any one of Claims 6 to 8, wherein each modulating means comprises a piece of piezo electric material secured to the optical fibre, or to the cable of which the optical fibre constitutes a component element.
Claim 12
Dependent Claim
20 words
A telecommunication system as claimed in any one of the preceding Claims,wherein the source of radiation is a gas laser.
References Cited (Backward Citations)
No citation records indexed.
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