Electrically Traceable and Identifiable Fiber Optic Cables and Connectors

• US 20080273844A1
• Filed: 05/02/2008
• Published: 11/06/2008
• Est. Priority Date: 05/04/2007
• Status: Active Grant

• Current Assignee: Telescent Inc.
• Original Assignee: Anthony Stephen Kewitsch
• Inventors: Kewitsch, Anthony S.
• Granted Patent: US 7,920,764 B2
• Time in Patent Office: Days
• US Class Current: 385/101
• CPC Class Codes: G02B 6/3895 identification of connection, e.g. right plug to the right socket or full engagement of the mating parts keying element on the plug or adapter G02B6/3831; keying element on the ferrule G02B6/3851; keying element for electrical connection H01R13/64
• CPC Class Codes: G02B 6/562 locatable, e.g. using magnetic means

Abstract

Composite fiber optic cables having exposed, conductive traces external to the cable jacket enable non-invasive, wireless electrical tone tracing of fiber optic cables. The cross sectional geometry of the fiber optic cable prevents conductive traces from short circuiting when abutting other cables or grounded conductive elements. Moreover, the structure allows convenient electrical contact to the conductive traces at any location along the longitudinal extent of the cable without requiring penetration of the cable jacket or removal of fiber optic connectors. Traceable fiber optic cables of various types are disclosed, including simplex, duplex and ribbon cables. Systems of traceable cables utilizing connectors with integrated electrical antenna elements attached to the conductive elements of cable and RFID tags for remote connector port identification are further disclosed.

Claims

1. A composite fiber optic cable including conductive elements for transferring signals separately from fiber optic transmissions to enable identification at a transmission site of end connections to a spatially separated remote site, comprising:

a fiber optic cable connection including a flexible jacket extending between the transmission site and the remote site, the flexible jacket including at least one internal plenum, and at least one external channel configured for receiving a conductive element having a known thickness;

at least one coated optical fiber element in the internal plenum of the fiber jacket and extending along its length between the transmission and remote sites, and

at least one electrically conductive element disposed in the at least one external channel of the flexible jacket substantially along its length and having the known thickness and including a conductive surface exposed to the exterior of the jacket, whereby an electromagnetic radiation signal on the at least one conductive element from a location along the length of the fiber optic cable device can be detected to identify connections at the remote site.

2. A composite cable in accordance with claim 1 above, wherein said at least one external channel is configured in a spiral path along the exterior of the flexible jacket, such that the conductive element in the external channel is tolerant to stresses induced by bending of the cable.

3. A composite cable in accordance with claim 1 above, including in addition an emitting and receiving element coupled to the conductive element at the remote site to extend the range over which identification tags responsive to emissions from the emitting and receiving element can be identified.

4. A composite cable in accordance with claim 3 above, wherein the at least one conductive element carries signals in the radio frequency range and where the emitting and receiving element is a radio frequency device.

5. A composite cable in accordance with claim 1 above, wherein the at least one conductive element is copper wire of about 0.05-0.15 mm diameter and the flexible jacket is a polymeric material selected from the class of materials including poly-vinyl chloride.

6. A composite cable in accordance with claim 1 above, wherein the flexible jacket has two internal plenums and two external conductive element receiving channels, the jacket having parallel and adjoined substantially circular peripheral surfaces united at a juncture region and defining external concavities at the juncture region, for separately receiving the conductive elements, wherein the conductive elements provide bilateral transmission paths.

7. A composite cable in accordance with claim 1, wherein the at least one conductive element comprises a strip layer of conductive material extending along the surface of the fiber jacket, the strip of conductive material being compatible in flexibility to the jacket material.

8. A composite cable in accordance with claim 1, wherein the jacket includes a plenum for receiving a plurality greater than two of fiber optic elements therein in a strip configuration, each of the fiber optic elements including a coated exterior and the cable further including at least two conductive element coupled to the jacket exterior and extending along the length thereof.

9. A composite fiber optic cable with capability for electronic detection at a transmission site of indicators from remote status points to enable physical tracing and identifying cable status within a fiber optic network installation comprising:

a length of flexible jacket extending between the transmission and remote sites, the flexible jacket having an asymmetrical cross-section with a major and minor axis and including at least one internal plenum for receiving optical fiber elements therein, the jacket further including one or more exterior channels for receiving conductive elements;

at least one coated optical fiber element disposed in the internal plenum portion of the flexible jacket and extending along its length; and

at least one electrically conductive element embedded in the external concavity of the jacket, the conductive element being dimensioned such that a conductive surface is exposed to the exterior of the jacket when the conductive element is embedded in position,

wherein the cable cross-section exhibits a moment of inertia along the major axis at least four times greater than the moment of inertia along the minor axis, and wherein at least one conductive element is disposed within 0.5 mm of the major axis, such that the conductive element is subjected, during bending of the cable, to less than 5% strain, when the cable is bent to a degree greater than the minimum bend radius of the fiber.

10. A composite fiber optic cable in accordance with claim 9, wherein the cross-sectional dimension of the cable parallel to the major axis is at least a factor of two greater than the minor axis.

11. A composite fiber optic cable in accordance with claim 9, wherein the at least one conductive element is 0.05-0.15 mm diameter copper wire and the flexible jacket comprises a polymeric material selected from the class of materials including poly-vinyl chloride.

12. In an electronic system used within a communications network which has fiber optic cables interfacing a central patching unit at the proximal ends of the cables and remote transmission equipment at the distal ends of the cables, an arrangement for determining and updating inventories of physical fiber optic cable connections, comprising:

a multiplicity of composite fiber optic cables each having a jacket with at least one internal plenum and receiving at least one optical fiber within the jacket and at least one conductive element along the length of the jacket, each fiber optic cable also including, at proximal ends thereof, first fiber optic connectors, and at the distal ends thereof, second fiber optic connectors;

the second fiber optic connectors including electrical antenna elements coupled to the different electrical conductive elements for efficiently coupling electromagnetic signals bi-directionally along the conductive elements from the distal ends in the network;

the first fiber optic connectors optically and electrically interfacing cable to the central patching unit;

radio frequency identification tag sources disposed adjacent to the second fiber optic connectors in the communication network, and

an electronic control unit coupled to the composite fiber optic cables at their proximal ends for transmission of signals along the cables to their distal ends, said control unit including a transmission subsystem launching excitation voltage signals of radio frequency onto the conductive elements of the composite fiber optic cables, thereby emitting radiation via the electrical antenna elements of sufficient strength to energize the remote radio frequency identifiers in the network such that they emit a characteristic electromagnetic signature for bi-directional transmission via the transmitting antenna back to the connectors at the proximal end for reception by the electronic control unit, whereby electromagnetic signatures can be identified and correlated with the inventory of physical fiber optic connections.

13. An electronic system in accordance with claim 12, wherein the characteristic electromagnetic signature is in the frequency range of 1 KHz to 10 GHz and wherein each radio frequency identification tag has a unique electronic identifier.

14. A system for independently transmitting electromagnetic radiation in both the optical and radio frequency spectra along a cable system, wherein:

the cable system is designed to emit less than 0.5 dB of optical power per km of cable and greater than 0.5 dB of radio frequency power per km of cable;

the system including optical fibers within a cable jacket and RF conductors external to said jacket;

both the optical fibers and the external RF conductors extending along the cable;

with electrical signal generation equipment at a transmission site for conductively coupling an electrical signal onto the RF conductors in the radio frequency spectrum at any location along the cable system without requiring penetration of the cable jacket, and

with wireless electrical signal detection equipment, including an amplification circuit at a remote site responsive to radio frequency spectrum,

whereby the amplification circuit can receive the electrical signal to identify and locate the optical fibers without interrupting transmission in the optical spectrum.

15. A system in accordance with claim 14, wherein the radio frequency spectrum is in the frequency range of 1 KHz to 10 MHz and the electrical signal detection equipment includes a high sensitivity wireless voltage probe comprising a high input impedance transistor stage for amplifying the radio frequency radiation characterized by the unique spectral signature.

16. A fiber optic patch cable system for use between first and second end points, to transmit optical and electrical signals between said end points, the system comprising a connector terminating at the second end point and providing low loss transmission of the optic signal to a mating connection, the system also including means for efficiently radiating the electrical signal into free space at the second end point to extend the range of a radio frequency identification tag located at the first end point;

a length of composite fiber optic cable joining the two end points, the composite fiber optic cable including at least one optical fiber and at least one electrical conductor, both the optical fiber and conductor lying co-extensively along the length of cable;

a connector at the first end point per each cable, the connector having a ferrule with internal optical contacts, the ferrule circumferentially surrounding one or more optical fibers and the electrical contacts attached to one or more electrical conductors thereby enabling low loss transmission of optical signals across a connection interface, and connection of electrical signals to an RF identification tag reader;

a terminating connector at the second end point with a second ferrule having internal optical contacts and circumferentially surrounding one or more optical fibers, the connector including an electrical coil attached to the one or more electrical connectors, such that the optical contacts enable the low loss transmission of optical signals and the electrical coil produces a time-varying electromagnetic field in the vicinity of the connector, and of sufficient strength to wirelessly couple to and read out a unique electronic signature of the radio identification tag situated in the vicinity of the connector.

17. A patch cable system in accordance with claim 16, wherein the electrical coil comprises a flexible, elastomeric boot surrounding the cable at the location where the second end point of the cable enters the connector body housing.

18. A patch cable system in accordance with claim 17, wherein the elastomeric boot is molded about the electrical coil wire form and the diameter of the wire comprising the coil is in the range of 0.2-0.5 mm.

19. A system for tracing the locations of electronic units that process signals from optical waveguides, the units being separately identified by passive radio frequency identification (RFID) tags proximate thereto, the system further including a multiplicity of optical fiber lines coupled individually to the different units at distal locations from the system, and comprising:

a plurality of conductive elements disposed along the lengths of the different fiber optic lines, and being positioned adjacent the fiber optic lines but separate therefrom along the length thereof to the distal locations;

a central operating system comprising an actuable low power transmitter and a multiplexer coupling the transmitter separately to the different lines;

a plurality of low power RF transmitters, each coupled to a different one of the conductive elements at a distal location electrically coupling to the RFID tags thereat, the power transmitted being sufficient to excite the passive RFID tag thereat, to generate an identification response of sufficient power to be returned bi-directionally to the central operating system as to the equipment status at that location, and the central operating system further including a radio frequency tag reader coupled to the multiplexer system for receiving the returned RFID tags and establishing the status of the related unit in the inventory.

20. A system as set forth in claim 19 above, wherein the conductive elements are disposed along the associated optical fiber lines in configurations which present external surface segments of conductive material therealong, and wherein the system includes probe means for engaging the surface conductive segments to excite RF signals therein at selected locations along the lengths of the lines.

21. A system as set forth in claim 19 above, wherein the transmitter exciting the terminal transmitters provides a power output of more than 0.5 dB per km of cable, and wherein the return signal from the RFID tag is of less than 0.05 mW.