Abstract:
A data transmission system forming a network including transmission line sections comprising traditional infrastructure such as AC power line (mains), twisted-pair (e.g. CAT-5) and coaxial cable wiring interconnected with a novel adapter to form a data system also providing data transfer over an extended length and diversity of connected equipment. Further combined with a data bridge connected to conventional format data (e.g. Ethernet) and to the traditional data infrastructure wiring, the novel adapter permits connection to any 2 of twisted pair/multi-pair, coaxial and power mains for data flow therebetween.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to data system transmission lines and apparatus, in particular to systems and apparatus for extended distance data transmission over conventional transmission lines. 
       BACKGROUND OF THE INVENTION 
       [0002]    Data transmission from point-to-point or via a long network cable often includes known infrastructure wiring, e.g. coaxial cable, twisted-pair or multi-pair (e.g. CAT-5) cable, and building wiring (power mains) as part of the system network. However, existing network standards for data transmission over twisted- or multi-pair (CAT-5) cable prescribes a maximum distance of 650 feet, whereupon a user may wish to have a network or point-to-point connection significantly in excess of that distance. Furthermore, installation guidelines and skills are well known for such traditional wiring, which may already be installed in certain structures. 
       SUMMARY OF THE INVENTION 
       [0003]    According to one embodiment of the present invention, a data transmission system is provided comprising a network including transmission line sections comprising traditional infrastructure wiring interconnected with a novel adapter. Further combined with a data bridge connected to conventional format data and to the traditional data infrastructure wiring, the novel adapter permits connection to any 2 of twisted pair/multi-pair, coaxial and power mains for data flow therebetween. 
     
    
     
       BRIEF DESCRIPTION OF THE INVENTION  
         [0004]    These and further features according to the present invention will be better understood by reading the following Detailed Description, taken together with the Drawing, wherein 
           [0005]      FIG. 1  is a schematic diagram according to an exemplary embodiment of a 3-port adapter according to the present invention; 
           [0006]      FIG. 2  is a block diagram of an exemplary network system provided according to the present invention; and 
           [0007]      FIG. 3  is a block diagram of an exemplary data bridge according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0008]    The present invention provides flexible interconnectivity between a diversity of media types. One embodiment  50  as shown in  FIG. 1  comprises a multi-port passive media coupler, including a “power line” port  52 , a twisted-pair port  54 , and a coaxial cable port  56 . The ports are mutually coupled with a transformer  60  including a winding  62 ,  64  and  66  connected to the ports  52 ,  54  and  56  respectively. The transformer typically comprises a core  68  including a ferrite core and the windings  62 ,  64  and  66  comprise one turn more or less considering the impedances to be achieved, would together side-by-side (‘trifilar’) and passing through a window or hole in a core structure which surrounds the windings to enhance the coupling of the data signal. Other transformer structures providing signal coupling with a pass-band corresponding to the data signal transmitted therethrough, e.g. 1-50 MHz in the present exemplary embodiment, may be incorporated. 
         [0009]    Further according to the embodiment  50 , the transformer coupling the media ports  52 ,  54  and  56  includes winding and related structure to reflect the impedance of one port to the other. Accordingly, the effective impedance of the “power line”, found to be around 50 ohms to which port  52  is connected, can be effectively matched to the impedance of a typical twisted-pair, having an impedance around 600 ohms or less and connected to port  54  or a coaxial cable (e.g. 50, 75, etc. ohm) connected to port  56 , vice-versa, or between any two ports. When media having the expected impedance are the appropriate port, the media coupler  50  provides an impedance-matched connection between differing media with the unused port being unterminated (open). However, further embodiments include the addition of a termination circuit  140  (being resistive, reactive or combination) connected to the port not connected to a media and adjusted or selected to provide impedance correction to media connected to the media coupler  50  other than the impedances for which the particular media coupler was provided. 
         [0010]    Frequently the connected medium includes signals that are not desired to be transferred to the other medium connected, or potentially harmful to the components (e.g. the transformer  60 ) of the media coupler  50 . Accordingly, a filter may be applied to any and all of the data ports or between the ports and the corresponding winding. An exemplary high pass filter  58  is shown including a capacitor  68  selected to allow the data signals to be efficiently coupled between the port  52  and the corresponding winding  62 , while providing a high rejection of the AC power line (mains, e.g. 120 Vac, 60 Hz) signal. The port  56  for coaxial cable is connected to winding  66  and the port  54  for twisted-pair cable is connected to winding  64 . However, further embodiments according to the present invention may include a passive or active filter selected to provide specific, high-pass, low-pass, band-pass, band-reject, equalization (delay, phase, frequency, etc.) characteristics. Furthermore, embodiments having ports connected to filters of differing filters selected to provide connection of data at differing frequencies over different ports such that more than 2 ports may be connected to a medium. 
         [0011]    An exemplary network (system)  100  as may be provided according to the present invention is shown in  FIG. 2 , wherein an exemplary twisted-pair medium  102 , such as included in a CAT-5 cable connected to a plurality of common RJ45 connectors  104  along its length, which may exceed a length that Ethernet format data may reliably be exchanged to data equipment connected thereto. A first exemplary data equipment  110  is connected to a data bridge  112  transforming to and from a format transferable over a power line via a port  114 , which may connected to the power line (not shown) to which the media coupler  150 A is connected, or the media coupler may be plugged directly into the data line port  114 . In turn, the twisted-pair port  116  of the media coupler  150 A is connected to a conveniently located twisted pair connector  102 , wherein the remaining port of the media coupler  150 A is typically open (unterminated). A second exemplary data equipment  120  is provided in  FIG. 2 , also having a power line data bridge  122  to which a media coupler  150 B is connected via a power line connection  124  (directly or via a power line, not shown). The media coupler  150 B is further connected by plugging into a convenient connector  104  along the length of the medium  102 , and the unused coaxial port of the media coupler  150 B is left open. Alternately, an impedance adjusting network  140  discussed above, may also be connected to the media coupler  150 B (or  150 A or  150 C) port not connected to a medium. 
         [0012]    A third exemplary data equipment  132  is connected to the medium  102  via a data bridge  132 , providing data communication according to a coaxial medium at a connection  134  and typically band-limited (e.g. to less than 50 MHz in one embodiment) to which a media coupler  150 C is connected. The twisted-pair port of the media coupler  150 C is connected to the medium  102  via a convenient connector  104  along its length. The power-line port of the media coupler  150 C is typically unterminated (open). 
         [0013]    The present invention also includes a system having a media coupler according to the present invention connecting the power line port and the coaxial cable port wherein the twisted-pair port is unterminated (open), similar to the embodiment  100  of  FIG. 1  but where the medium ( 102 ) is different, e.g. comprising a power line or coaxial cable medium. Further systems according to the present invention include point-to-point connection connected at ends of a selected power-line, twisted-pair or coaxial cable medium, or another medium for which an appropriate transformer winding, filter or other media coupler component is selected to provide the desired impedance matching, isolation, filtering, signal loss, etc. characteristic. 
         [0014]    An exemplary data bridge  150  according to the present invention is shown in  FIG. 3 , wherein the power line or mains  260  is shown with outlet  280  disposed therealong, and may include separate branch circuits having a common junction with sufficient data signal coupling to maintain acceptable fidelity of data transmission thereover in the signal range of interest for the protocol or format of the data bridge  200 . 
         [0015]    A connection is made between a bidirectional high pass filter (HPF)  204  and the mains outlet  280  and/or to the power line port  52  of the data coupler  50  according to the present invention via connector  202  typically a power line (mains) plug which may be connected to power this or other equipment (not shown), wherein the HPF  204  removes much if not all of the AC power (and other low frequency) signals leaving the path intact for signals corresponding to the data signals applied thereover. The other side of the HPF  204  is connected to an analog front end (AFE)  206  which applies the digital signal generated by the transmitter portion of the PLC transceiver  208  to the mains  260  as a suitably conditioned signal, and provides a suitably conditioned (e.g. amplified/attenuated, shaped, etc.) return path from the mains  260  to the receiver portion of the PLC transceiver  208 . The PLC transceiver  208  can communicate directly with connected data equipment (not shown) connected to jack  212 A or other suitable connector, or may be connected to multiple other data equipment (also not shown) by jacks  212 B- 212 D via a data switch  210  or equivalent. 
         [0016]    In the embodiments shown, the data bridge  112  provides data to the power line (mains) port  114  according to the IEEE Ethernet Over Powerline standards, also described in the HomePlug white paper Doc. HPAVWP-050818, incorporated by reference. However, the system and media coupler according to the present invention accommodates and includes in its scope other common or custom media formats. Further modifications and substitutions made by one of ordinary skill in the art are within the scope of the present invention, which is not to be limited, except by the claims, which follow.