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WO1999036984A1 - Procede et appareil permettant de transmettre de multiples signaux electriques a largeurs de bande importantes - Google Patents

Procede et appareil permettant de transmettre de multiples signaux electriques a largeurs de bande importantes Download PDF

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Publication number
WO1999036984A1
WO1999036984A1 PCT/US1998/000747 US9800747W WO9936984A1 WO 1999036984 A1 WO1999036984 A1 WO 1999036984A1 US 9800747 W US9800747 W US 9800747W WO 9936984 A1 WO9936984 A1 WO 9936984A1
Authority
WO
WIPO (PCT)
Prior art keywords
conductors
pairs
balanced mode
mode signals
signals
Prior art date
Application number
PCT/US1998/000747
Other languages
English (en)
Inventor
Barry Thornton
Original Assignee
Int Labs, 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
Application filed by Int Labs, Inc. filed Critical Int Labs, Inc.
Priority to PCT/US1998/000747 priority Critical patent/WO1999036984A1/fr
Priority to AU61319/98A priority patent/AU6131998A/en
Publication of WO1999036984A1 publication Critical patent/WO1999036984A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/20—Arrangements affording multiple use of the transmission path using different combinations of lines, e.g. phantom working

Definitions

  • the invention relates generally to the transmission of analog and digital signals and, more particularly, to a method and apparatus for enabling the transmission of high bandwidth analog and digital data over cable lengths of more than 1000 feet through low cost semishielded or unshielded four wire cable.
  • the primary issue limiting growth has been the diversity of signals that must be transmitted and the specialized requirements associated with the transmission of each type of signal.
  • installation of smart home wiring necessarily includes a variety of cables, each with its own particular performance, termination, and installation problems.
  • the office-place would benefit from technology that would enable computer images, referred to as RGB or VGA signals, and audio to be transmitted throughout the office without the need for installing a variety of additional cables and wiring.
  • One application for such technology would be the ability to permit someone else in the office building to view the output of another person's computer monitor on his own monitor, while enabhng a hands-free voice intercom for discussion of same. This would enable both parties to view the same monitor output in real time.
  • the "viewer” would be able to watch the other party's mouse movements, cursor activity, typing, and such, just as if they were standing behind the person and looking over the shoulder.
  • the above- described objectives cotdd be achieved through use of a computer information network; however, this would be considered by most to be a questionable use of valuable network time.
  • the first user if a first user wants to obtain a copy of a document a second user is working on, the first user must download the document through the network server, in which case a copy of the document exists on the first user's computer, which may be undesirable for security reasons, and the second user cannot access the document until it is closed by the first user.
  • specialized cabling could be installed for achieving the aforementioned objectives.
  • the installation of the necessary wiring would be extremely expensive, not to mention time consuming.
  • older buildings typically will not be able to withstand the added weight of the additional cables and wiring, in which case existing wiring must be removed before the new wiring can be installed, resulting in a great deal of added expense.
  • teleconferencing which is presently accomplished through a mobile teleconferencing system or a specialized room or site, in which case the hardware and outside interface equipment are not located in a secure and electronically proper room.
  • Fig. 1 illustrates a cable 108 configured in such a manner. As shown in Fig. 1, the components A+, A-, of a first balanced mode signal A are respectively applied to a first pair of conductors 110a, 110b, thereby creating a virtual ground plane 112.
  • the components B+, B-, of a second balanced mode signal B are respectively applied to a second pair of conductors 114a, 114b, and create a virtual ground plane 116.
  • the first pair of conductors 110a, 110b are positioned such that they lie in the virtual ground plane 116
  • the second pair of conductors 114a, 114b are positioned such that they lie in the virtual ground plane 112. In this manner, energy occurring in the virtual ground plane of one of the signals is not induced into the energy transfer of the other.
  • conductor pairs 110a, 110b, and 114a, 114b, and the respective signals carried thereon are electrically isolated from one another.
  • Fig. 1 suffers certain deficiencies, not the least of which is the high conductor-to-signal ratio, making the technique costly and inefficient.
  • each cable is capable of carrying only two signal channels.
  • an additional conductor pair must be installed. This can be accomplished by using three individual shielded twisted pair cables using the shield for inter-channel isolation.
  • this solution while conceptually simple, is expensive, cumbersome, and, because it requires the installation of additional cables, labor intensive.
  • the present invention accordingly, provides a method and apparatus for enabhng the transmission of high bandwidth analog and digital data over cable lengths of more than 1000 feet through low cost semishielded or unshielded four wire cable, thereby overcoming or reducing disadvantages and limitations associated with prior methods and systems.
  • three balanced mode signals are transmitted using four conductors.
  • the components A+ and A- of a first balanced mode signal A are respectively carried on a first pair of conductors
  • the components B+ and B- of a second balanced mode signal B are respectively carried on a second pair of conductors
  • the components C+ and C- of a third balanced mode signal C are respectively carried on a pair of conductors synthesized through the commonality of the first and second conductor pairs, respectively.
  • an encode, or send, resistor matrix comprises sources for generating each of the components of the three balanced mode signals and eight equal resistors.
  • Each of four conductors carries the summed current of two of the source signal components.
  • each of four resistor pairs comprising the eight resistors function so as to create summing nodes at the conductors.
  • the components of the signal C are shared by the first and second pairs of conductors.
  • a decode, or receive, resistor matrix essentially undoes the signal matrixing that occurred at the send matrix.
  • the respective outputs are fed to balanced detectors offering high common mode rejection.
  • the number of conductors used to implement the technique of the present invention is symmetrically expandable in units of 4 n , where n is a natural number without limit, with a signal-to-conductor ratio of (N-l)-to-N, where N is the number of conductors 4 n . Therefore, fifteen signals can be transmitted using sixteen (4 f conductors, 63 signals can be transmitted using 64 (4 3 ) conductors, and so on.
  • Piggybacking and “bidirectionality.”
  • Piggybacking is the process by which a low-bandwidth signal, such as a remote control signal, is added onto a higher bandwidth signal, such as a television signal.
  • Bidirectionality is a process by which signals can be sent in opposite directions simultaneously on the same cable to enable activities such as teleconferencing, video intercom, computer data communication, and the like.
  • a technical advantage achieved with the invention is that it can be implemented using existing surplus telephone wiring in a building, such that no additional cabling is necessary.
  • Another technical advantage achieved with the invention is that all signal transmission is performed in a balanced mode, providing extremely high external noise rejection.
  • connector-to-channel ratio is that of a common ground unbalanced connectivity system.
  • Yet another technical advantage achieved with the invention is that it permits the use of very low performance cable and connectors for the connectivity of multiple high speed analog and digital signals and it enables the transmission of such signals through longer lengths of cable than are normally associated with the sources and signals involved.
  • Yet another technical advantage achieved with the invention is its cost effectiveness, in that it may be implemented using cheaper or preexisting cabling system for various applications, it extends the length of cable range without requiring many, if any, booster amplifiers, and it provides accessibility to points previously too distant for effective cabling.
  • Yet another technical advantage achieved with the invention is that it provides high common mode signal rejection, thereby eliminating noise that even shielded coaxial cable cannot eliminate.
  • Another technical advantage achieved with the invention is that its full floating signal transfer mode ehminates ground loops and AC mains power hum.
  • Fig. 1 illustrates a prior art method of winding four conductors together as a single cable for transmitting two signal pairs thereon.
  • Fig. 2 illustrates a four-conductor cable configured for implementing the technique of the present invention.
  • Fig. 3 is a block diagram of an encode, or send, resistor matrix of the present invention.
  • Fig. 4 is a block diagram of a decode, or receive, resistor matrix of the present invention.
  • Fig. 5 is a schematic block diagram of the send and receive matrices of Figs 3 and 4.
  • Fig. 6 illustrates the symmetric expandability of the system of the present invention.
  • Fig. 7A illustrates an example of point-to-point linkage for use in transmission of RGB signal in accordance with the features of the present invention.
  • Fig. 7B illustrates an example of network linkage for use in transmitting RGB signals in accordance with the features of the present invention.
  • Fig. 7C illustrates an example of distribution linkage for use in transmitting RGB signals in accordance with the features of the present invention.
  • Fig. 8 illustrates an example of a home network with central distribution for use in transmitting composite video with stereo audio signals in accordance with the features of the present invention.
  • Figs. 9A and 9B are schematic block diagrams of send and receive circuits, respectively, for a particular RGBHV implementation of the present invention.
  • Fig. 10 illustrates an alternate embodiment of a four-conductor cable configured for implementing the technique of the present invention.
  • Fig. 1 illustrates a prior art method of winding four conductors together as a single cable for transmitting two signal pairs, wherein two virtual ground planes created thereby are used for isolating the signal pairs.
  • a cable 208 which is physically identical to the cable 108 shown in Fig. 1, comprises a first pair of conductors 210a, 210b, to which the components A+, A-, of a first balanced mode signal A are respectively applied, thereby creating a virtual ground plane 212, and a second pair of conductors 214a, 214b, to which the components B+, B-, of a second balanced mode signal B are respectively applied, thereby creating a virtual ground plane 216.
  • a first pair of conductors 210a, 210b to which the components A+, A-, of a first balanced mode signal A are respectively applied, thereby creating a virtual ground plane 212
  • a second pair of conductors 214a, 214b to which the components B+, B-, of a second balanced mode signal B are respectively applied, thereby creating a virtual ground plane 216.
  • the first pair of conductors 210a, 210b are positioned such that they lie in the virtual ground plane 216, while the second pair of conductors 214a, 214b, are positioned such that they lie in the virtual ground plane 212, such that conductor pairs 210a, 210b, and 214a, 214b, and the respective signals carried thereon are electrically isolated from one another.
  • the components C+, C-, of a third balanced mode signal C are respectively applied to a third pair of conductors synthesized through the commonality of the conductor pairs 210, 214, and designated in Fig. 2 by reference numerals 217a, 217b, thereby creating a third virtual ground plane 218 wherein signal energy can be transferred without disturbing or corrupting the transmission of other signals being transmitted via the cable 208.
  • Fig. 3 illustrates an encode, or send, resistor matrix 300 for sending signals A+, A-, B+, B-, C+, and C-, on the conductors 210a, 210b, 214a, 214b.
  • the matrix 300 comprises a plurality of low impedance balanced signal sources for generating the signals A+, A-, B+, B-, C+, and C-, and eight equal resistors R1-R8.
  • each resistor pair Rl and R2, R3 and R4, R5 and R6, and R7 and R8 functions so as to create summing nodes at the conductors 210a, 210b, 214a, 214b, and to set the back termination and natural impedance requirements of the cable.
  • Fig. 4 illustrates a decode, or receive, resistor matrix 400 for essentially undoing the signal matrixing performed by the send matrix 300.
  • the receive matrix comprises outputs for each of the signals, as well as five (5) resistors R13-R17.
  • the resistors R13-R16 function to create the null signal nodes resulting in the signals C+ and C-, and to set the back termination load for the cable.
  • the resistor R17 functions as a back termination for the synthetic balanced cable impedance.
  • Fig. 5 is a schematic block diagram of a complete system 500 embodying features of the present invention and comprising a send matrix 502 identical to the send matrix of Fig. 3, and a receive matrix 504 identical to the receive matrix of Fig. 4.
  • the impedance Z of the cable is R/2 ohms ( ⁇ )
  • the resistance of each of the resistors in the send matrix 502 will be equal to R ⁇ , i.e., twice the impedance Z of the cable.
  • the resistances of the resistors R13- R16 in the receive matrix 504 will be equal to R/4 ⁇ , i.e., half the impedance Z of the cable.
  • the load resistor R17 for signal C which has a resistance of 3R 4 ⁇ , enables the independent adjustment of the adjacent conductor pairs while the load resistor pairs for signals A and B set the impedance of the opposite pairs.
  • the signal carrying medium was described as a four conductor cable, e.g., cable 208 (Fig. 2). It will be recognized, however, that a four conductor cable can be considered to be a single conductor in an expansion up to the next power of four. As shown in Fig. 6, this expands the signal density to fifteen channels for sixteen conductors.
  • a cable consisting of four individual conductors W1-W4 is rematrixed for use as a composite conductor W.
  • cables each consisting of four individual conductors X1-X4, Y1-Y4, and Z1-Z4, are rematrixed for use as composite conductors X, Y, and Z, respectively.
  • fifteen signals can be transmitted via 16 single conductors W1-W4, X1-X4, Y1-Y4, and Z1-Z4, three signals via each group of conductors W1-W4, X1-X4, Y1-Y4, and Z1-Z4, as described above with reference to Figs. 2-5 and three signals via the group of composite conductors W, X, Y and Z.
  • the number of conductors N may be expanded in units of 4 n (where n is a natural number, i.e, a positive integer) without limit, such that N-l signals may be carried by the N conductors.
  • n is a natural number, i.e, a positive integer
  • N-l signals may be carried by the N conductors.
  • three signals can be transmitted using four (4 1 ) conductors, fifteen signals can be transmitted using sixteen (4 2 ) conductors, 63 signals can be transmitted using 64 (4 3 ) conductors, and so on.
  • the technique of the present invention is applicable to consumer, contractor, industrial and computer markets and is generally manifested in either of two forms; specifically, (1) RGB plus sync, or (2) composite video with stereo audio.
  • RGB plus sync wide bandwidth, e.g., 25 MHz
  • RGB video data with imbedded horizontal synchronization ("H") and vertical synchronization ("V") signals are transmitted using a single four conductor bundle.
  • H horizontal synchronization
  • V vertical synchronization
  • RGB with imbedded H and V (“RGBHV") signals from a device 702, which may be, for example, a camera, video tape recorder ("VTR"), satellite downlink, or computer, are transmitted directly to a device 704, which may be, for example, a video monitor, a VTR, an satellite uplink, or a computer, via a four-conductor bundle 706.
  • VTR video tape recorder
  • a device 704 which may be, for example, a video monitor, a VTR, an satellite uplink, or a computer, via a four-conductor bundle 706.
  • Other examples of point-to- point applications include all other video sources from CGA through HDTV, as well as applications that currently employ cable connectivity for video, such as broadcast, production, security, teleconferencing, medical, industrial and consumer environments.
  • Fig. 7B illustrates an application 710 in which a network linkage is used. As shown in Fig.
  • RGBHV signals are transmitted to and from several devices 712 via one or more four conductor buses, collectively designated by a reference numeral 714.
  • a user selects a channel to be shared with others via the link.
  • the combination of the low cost of cable, installation, terminations and associated hardware makes the technique of the present invention practical in most situations in which a computer network, typically some type of LAN, needs to be kept unloaded for raw computer data use.
  • Fig. 7C illustrates application of a distribution linkage. Distribution is a special case of point-to-point in which multiple feeds are required, such as arrival and departure information in airports or information systems in financial institutions.
  • RGBHV signals from a source 721 are distributed to several devices 722 via one or more four conductor buses 724.
  • a consumer home entertainment network 800 In composite video with stereo audio applications, high performance baseband video is combined with low noise and distortion stereo audio for use in either a consumer home entertainment network or in general multimedia use.
  • a consumer home entertainment network 800 the bidirectionality and piggybacking attributes of the technique of the present invention are exploited to enable devices in various rooms 810, including video and stereo audio components, collectively designated by a reference numeral 814, and one or more remote control units 816, to communicate with a central entertainment control center 812.
  • An alternative to the network 800 would be a variant of the RGB network shown in Fig. 7B, wherein additional source systems, such as VTRs or laser players, in individual rooms could be added to the network for remote access.
  • both VTRs could be put on the network 800 such that the tapes could be viewed from monitors in the other rooms 810.
  • the bidirectionality and piggybacking features of the technique could be used to expand the information carried on the network 800 to include telephone and intercom signals, as well as security camera feeds.
  • Figs. 9A and 9B are schematic diagrams of send and receive circuits, respectively, for a particular RGBHV implementation of the present invention. Because the implementation details of the schematic diagrams shown in Figs. 9A and 9B will be apparent to a skilled artisan from the face thereof, they will not be described in further detail herein.
  • circuits such as those shown in Figs. 9A and 9B would be housed in "black boxes" connected to conventional telephone wiring of the building in which the system is to be used via an RJ connector. Similarly, devices for generating or receiving the signals being transmitted through the system would be connected to the black box in a conventional manner. In this manner, existing four-wire telephone cable may be used to transfer a plurality of wideband signals throughout the building.
  • Figs. 10-12 are schematic block diagrams of alternate embodiments of the complete system 500 shown in Fig. 5 embodying features of the present invention.
  • Fig. 10 for example, comprises a send matrix 1002 similar to the send matrix 502 of Fig. 5, and a receive matrix 1004 similar to the receive matrix 504 of Fig. 5.
  • the send matrix 1002 comprises resistors R11-R18 each of which has a value of Rm which is chosen for precision and low current needs.
  • the cable has an impedance Z of Rz ⁇ which becomes the sole determinant of the impedance matching to the cable and can be chosen as would any back terminated drive line driver source resistors.
  • Eight additional resistors R21-R28 are provided as shown in Fig.
  • Fig. 11 is similar to Fig. 10 except that each of the resistors R25-R28 have resistances of Rm 2 , and two additional resisters R29 and R30, each having a resistance of Rz, of are connected in parallel as shown in Fig. 11.
  • the embodiments of Figs. 5, 10, and 11 may be configured to provide for a bi-directional link as depicted in Fig. 12. In the configuration of Fig. 12, the channels have been doubled back upon themselves permitting two-way signal passage on the same lines by using input- output subtraction at each output. Because the implementation details of the schematic diagrams shown in Figs.
  • the present invention is not limited to wide bandwidth use, e.g., use in bandwidths exceeding 25 MHz, but may be used with narrower bandwidths as well, or even wider bandwidths if compensation is provided, for example, by reducing the length of cable over which signals are sent.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

Cette invention concerne un procédé et un appareil qui permettent de transmettre des données analogiques et numériques à largeur de bande importante sur des distances de câblage de plus de 1000 pieds et par l'intermédiaire de câbles semi-blindés ou non blindés à quatre conducteurs. Trois signaux de mode symétrique sont transmis à l'aide de quatre conducteurs (210a, 210; 214a, 214b). Les composantes (A+, A-) d'un premier signal de mode symétrique (A) sont transmises respectivement par la première paire de conducteurs (210a, 210b), tandis que les composantes (B+, B-) d'un deuxième signal de mode symétrique (B) sont transmises respectivement par la deuxième paire de conducteurs (214a, 214b). Les composantes (C+, C-) d'un troisième signal de mode symétrique (C) sont quant à elles transmises respectivement par une paire de conducteurs qui a été synthétisée par la banalisation de la première et de la deuxième paires de conducteurs (210a, 210; 214a, 214b), respectivement. Cette technique permet de créer un plan de sol virtuel complémentaire (218) dans lequel l'énergie d'un signal peut être transmise sans qu'il y ait d'interférences avec d'autres signaux transmis sur les paires de conducteurs symétriques.
PCT/US1998/000747 1998-01-14 1998-01-14 Procede et appareil permettant de transmettre de multiples signaux electriques a largeurs de bande importantes WO1999036984A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/US1998/000747 WO1999036984A1 (fr) 1998-01-14 1998-01-14 Procede et appareil permettant de transmettre de multiples signaux electriques a largeurs de bande importantes
AU61319/98A AU6131998A (en) 1998-01-14 1998-01-14 Method and apparatus for enabling the transmission of multiple wide bandwidth electrical signals

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1998/000747 WO1999036984A1 (fr) 1998-01-14 1998-01-14 Procede et appareil permettant de transmettre de multiples signaux electriques a largeurs de bande importantes

Publications (1)

Publication Number Publication Date
WO1999036984A1 true WO1999036984A1 (fr) 1999-07-22

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AU (1) AU6131998A (fr)
WO (1) WO1999036984A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003092214A1 (fr) * 2002-04-26 2003-11-06 Freescale Semiconductor, Inc. Procede et appareil pour trasmettre 3 signaux differentiels avec 2 paires de cables
US6844631B2 (en) 2002-03-13 2005-01-18 Freescale Semiconductor, Inc. Semiconductor device having a bond pad and method therefor
EP2209293A1 (fr) * 2000-09-21 2010-07-21 MOSAID Technologies Incorporated Système de communication téléphonique et méthode sur câblage de réseau local
GB2468925A (en) * 2009-03-27 2010-09-29 Cable Sense Ltd Coupling a signal to and/or from a twisted pair cable
USRE43774E1 (en) 2007-04-12 2012-10-30 Commscope, Inc. Of North Carolina Systems and methods of identifying patch cord connections in a communications patching system using common mode transmission
GB2503636A (en) * 2009-03-27 2014-01-01 Cable Sense Ltd Non-contact coupling of a signal to and from a twisted pair cable

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR644871A (fr) * 1929-04-27 1927-10-16 Soc Et Liaisons Telephoniques Système de combinaisons des circuits téléphoniques
US2086629A (en) * 1936-04-14 1937-07-13 Bell Telephone Labor Inc Shielded cable system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR644871A (fr) * 1929-04-27 1927-10-16 Soc Et Liaisons Telephoniques Système de combinaisons des circuits téléphoniques
US2086629A (en) * 1936-04-14 1937-07-13 Bell Telephone Labor Inc Shielded cable system

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2209293A1 (fr) * 2000-09-21 2010-07-21 MOSAID Technologies Incorporated Système de communication téléphonique et méthode sur câblage de réseau local
US7843799B2 (en) 2000-09-21 2010-11-30 Mosaid Technologies Incorporated Telephone communication system and method over local area network wiring
US8619538B2 (en) 2000-09-21 2013-12-31 Mosaid Technologies Incorporated Communication system and method over local area network wiring
US8817779B2 (en) 2000-09-21 2014-08-26 Conversant Intellectual Property Management Incorporated Telephone communication system and method over local area network wiring
US6844631B2 (en) 2002-03-13 2005-01-18 Freescale Semiconductor, Inc. Semiconductor device having a bond pad and method therefor
WO2003092214A1 (fr) * 2002-04-26 2003-11-06 Freescale Semiconductor, Inc. Procede et appareil pour trasmettre 3 signaux differentiels avec 2 paires de cables
USRE43774E1 (en) 2007-04-12 2012-10-30 Commscope, Inc. Of North Carolina Systems and methods of identifying patch cord connections in a communications patching system using common mode transmission
GB2468925A (en) * 2009-03-27 2010-09-29 Cable Sense Ltd Coupling a signal to and/or from a twisted pair cable
US8008986B2 (en) 2009-03-27 2011-08-30 Cable Sense Limited Apparatuses and methods for coupling a signal to and/or from a cable
GB2503636A (en) * 2009-03-27 2014-01-01 Cable Sense Ltd Non-contact coupling of a signal to and from a twisted pair cable
GB2468925B (en) * 2009-03-27 2014-01-01 Cable Sense Ltd Apparatuses and methods for coupling a signal to and/or from a cable
GB2503636B (en) * 2009-03-27 2014-05-07 Cable Sense Ltd Apparatuses and methods for coupling a signal to and/or from a cable

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