CA2264847C - Data communication using power lines - Google Patents

Abstract

The apparatus uses electric power lines (100) to send and receive command, control, and data signal structures. Message signals are superimposed upon t he AC power signals present on existing power lines (100). Transmit and receive sets (10 and 20) are equipped with a unique individual coding to complete th e communication links. When a message signal is sent onto the line (100) the unique code of the sending unit (10) is placed at a predetermined position i n the transmitted signal. Also the intended receiving unit code is placed in t he message signal. An individual receiving network at a given location will be activated only when its unique code has been placed into a message on the li ne (100) sent by another unit. This coding ensures that only the intended location receiver will be able to trap the signal. The signals will be mid t o high frequency and will be composed of low level logic/digital bits.

Description

CA 02264847 1999-03-02W0 98/ 10579 PCT/U S96/ 14371DescriptionDATA COMMUNICATION USING POWER LINESTechnical FieldThe present invention relates to datacommunication via power lines. More specifically, itrelates to a system of sending signals down theexisting power lines to operate such devices asremote controls for VCR’s, personal computers,security systems, and the like. The possible usesfor this invention are endless and it is thereforehard to pinpoint exactly what fields of humanendeavor stand to benefit most from the invention.Certainly the field of medicine stands to reapsubstantial benefits because of the increasedpossibilities of transmission of digitized computermedical information. Remote areas, served byelectrical power lines but not having telephonelines, may now access all sorts of digitalinformation resources previously unavailable.Marketing and service information for all sorts ofproducts will gain an instant increase in the numberof potential buyers by the use of this invention.CA 02264847 1999-03-02W0 98/ 10579 PCT/U S96/ 14371Thus it can be seen that the potential fields ofuse for this invention are myriad, and the particularpreferred embodiment described herein is in no waymeant to be limiting the particular field chosen forexposition of the details of the invention.CA 02264847 1999-03-02WO 98/10579 PCT/US96/ 143713Discussion of the Prior Art In the past, it has been attempted to providetelephone communications to rural areas, not servedby telephone lines. Power lines that were widelyinstalled with the assistance of the RuralElectrification Administration of the United Statesgovernment were commonly used. These known devices,although they were broadly means for providingcommunication over a power line grid, were strictlyanalog in nature. They were not particularlysuccessful because of the inherent limitations of theanalog bandwidth and their focus on the transmissionof voice signals only. The main drawback was thatonly one call could be handled at a time.Eventually, nearly all households and businessesin this country became wired with telephonecircuitry. Over the years the introduction ofdigital computers and the corresponding introductionof digital communications took advantage of thenearly universal telephone hookups in this country.Almost all the equipment designed for digitalcommunication was designed to use the existingtelephone lines. The lowly electrical power line wasforgotten as to its potential for carryinginformation communication as well as power.CA 02264847 1999-03-02WO 98/10579 PCT/US96/143714As the world moves to a more global economy,there now exist many third world countries withelectric power lines but having sparse, or none atall, telephone wiring. The need therefore exists,much as in the early rural United States, for adevice providing communications ability to the commonelectrical power line. Today, however,"communications ability" means much more than theearly voice communication envisioned by the earlypatents. It means control of the operation of allsorts of electrical appliances as well as thetransmission, reception, and storage of vast amountsof textual and graphical information. To myknowledge, there has not, until now, been an attemptto apply sophisticated communications technology toan existing electrical power line grid. As will beseen, the simplicity and effectiveness of myinvention is not rivaled in the prior art.The following pertinent prior art was discoveredin a search conducted at the United States Patent andTrademark Office.United States Patent No. 5,051,720, issued toKittirutsunetorn on September 24, 1991, shows aremote control system using the power line of aremote site. This patent indicates many of theCA 02264847 2001-04-23communications abilities envisioned by the instantinvention. The patented system of controlling powerat a remote site includes a two channel modem havinga first channel dedicated for transmitting powercontrolling messages to power control modules and asecond channel dedicated to transmitting datamessages to computerized equipment. The powercontrol modules include a master control module whichis plugged into a power line extending through theremote site and one or more slave modules alsocoupled to the remote site power line for receivingtherethrough power control signals transmitted by themaster control unit. A user, located at a sitedistant from the remote site, may turn power on, off,or dim the power to any of a plurality of applianceswhich are coupled to the remote power line by way ofslave power control units.Thus, U.S. Patent No. 5,051,720 shows control ofseveral sorts of equipment through an existinghousehold power line, U.S. Patent No. 5,051,720. Thepatent teaches how one may control computers,printers, alarm systems, telephone answeringmachines, lighting, video recorders, magnetic taperecording machines and other remote appliances simplyby plugging them in to a power lineCA 02264847 1999-03-02WO 98/10579 PCT/US96/ 143716circuit at a given site. The patent does not use theexisting power line or power line grid between thelocal and remote site to transmit the controlsignals.By contrast, the device of the instant inventionuses the main electrical power lines for transmissionof the control signals to the various controlledequipment. There is no need to use a conventionaltelephone line for the operation of this invention.The instant invention proposes transmitting codedsignals over a line similar to the telephone lineused by the above patent and others. However, amajor difference is that the transmission is notdependent on the existence of any telephone line orany other sort of link such as radio or microwave.United States Patent No. 2,264,395, issued toMitchell on December 2, 1941, shows a power linecarrier frequency telephone system. The patent showsa line for transmitting electric power, for example,of relatively high voltage and low frequency betweentwo or more points and to a plurality of powerconsumers, some or all of whom, together with othersin the locality through which the line extends,desire telephone service. Telephone subscribersstations are coupled to the power line and areCA 02264847 1999-03-02W0 98/ 10579 PCT/U S96/ 143717adapted to receive and transmit telephone signals onhigh frequency or carrier waves. At each station andat the central office for the system, means areprovided for modulating the carrier waves fortransmission outgoing from the station or office, andfor demodulating a modulated carrier wave incoming tothe station or office. A single source of carrierwave, common to the system, is located at the centraloffice, or at one of the stations, or may be coupledto the power line at some point along the lineoutside of a station or the central office. Becausethe distances between stations and between a stationand the central office may be appreciable and willvary with the stations involved in a particular call,there may be phase differences between the carrierwave at the called or calling station and that of thecalling or called station. That is to say, there maybe phase differences in transmission occurringbetween the carrier wave employed for modulation andthe carrier wave employed for demodulation. Anyadverse effect, i.e., loss in demodulation output atthe receiving station, that might follow from such acondition may be precluded by arranging the stationsand the central office to transmit and receive onlythe carrier wave and one side—band of the modulatedcarrier wave. When a pair of stations are using thetelephone capabilities of the patented system, otherCA 02264847 2001-04-23users are essentially blocked from access to preventpotential interference. Thus, U.S. Patent No.2,264,395 teaches transmission of analog signals bysuperposition of high frequency carrier waves uponnormal power lines.By contrast, the device of the instant invention,is intended to transmit coded digital signals overexisting electric power lines. The above mentionedproblems of phase difference and potentialinterference are circumvented. By using existinghigh speed digital packet transfer technology andunique coding for individual users it is anticipatedthe instant invention will be accessible to manysimultaneous users on the same electrical power grid.United States Patent No. 2,264,396, issued toMoore on December 2, 1941, shows a device similar tothat discussed above with respect to the patent toMitchell. A different modulator-demodulator circuitis shown in the patent to Moore. When a pair ofstations are using the telephone capabilities of thepatented system, other users are essentially blockedfrom access to prevent potential interference. Thus,U.S. Patent No. 2,264,396 teaches transmission ofanalog signals by superposition of high frequencycarrier waves upon normal power lines.CA 02264847 2001-04-23By contrast, the device of the instant invention_is intended to transmit coded digital signals overexisting electric power lines. The above mentionedproblems of phase difference and potentialinterference are circumvented. By using existinghigh speed digital packet transfer technology andunique coding for individual users it is anticipatedthe instant invention will be accessible to manysimultaneous users on the same electrical power grid.United States Patent No. 2,032,360, issued toGreen on March 3, 1936, shows a power line carriersystem. The patented device shows the use of currenttransformers allowing impedance matching of theoverall network. Thus, U.S. Patent No. 2,032,360teaches transmission of analog signals bysuperposition of high frequency carrier waves uponnormal power lines.By contrast, the device of the instant inventionis intended to transmit coded digital signals overexisting electric power lines. The above mentionedproblems of phase difference and potentialCA 02264847 1999-03-02W0 98/ 10579 PCT/US96/ 1437110interference are circumvented. By using existinghigh speed digital packet transfer technology andunique coding for individual users it is anticipatedthe instant invention will be accessible to manysimultaneous users on the same electrical power grid.It will be noted that all the prior art devicesrequire either a telephone line for the transmissionof digital signals or abandon digital signalsentirely in favor of frequency modulated signals ifthey use an electrical power line.None of the above inventions and patents, takeneither singly or in combination, are seen to describethe instant invention as claimed.CA 02264847 1999-03-02W0 98/ 10579 PCT/U S96] 1437111Disclosure of the InventionBriefly, the invention conceives the use ofelectric power lines to send and receive command,control, and data signal structures. The transmitand receive sets are equipped with a uniqueindividual coding (for identification and security)to complete the communication links. When a messagesignal is sent onto the line the unique code of thesending unit is placed at a predetermined position inthe transmitted signal, such as in the header. Alsothe intended receiving unit code is placed in themessage signal. In this manner, an individualreceiving network at a given location will beactivated only when its unique code has been placedinto a message on the line sent by another unit.This coding ensures that only the intended locationreceiver will be able to "trap" the signal. Thesignals sent will be mid to high frequency and willbe composed of low level logic/digital bits.Accordingly, it is a principal object of theinvention to provide a new and improved datacommunication system using electric power lines whichovercomes the disadvantages of the prior art in asimple but effective manner.CA 02264847 1999-03-02W0 98,105” PCT/US96ll437112It is a major object of this invention toprovide an improved communication system which doesnot rely in any way on telephone wiring or telephoneswitching networks for its operation.It is another object of the invention to providean improved communication system which will complywith all Federal Communications Commissionregulations concerning radiated emissions.It is another object of the invention to providean improved communication system which will operateat a high enough frequency so as not interfere in anyway with the primary function of electric power linesof conducting electric power for use by subscribersin the operation of electric appliances.It is another object of the invention to providean improved communication system which will operateat a low enough frequency so that efficientpropagation of communication signals down powertransmission lines can be achieved.It is another object of the invention to providean improved communication system which will operateat close to zero phase angle so as not to interferewith or affect the electric utility load criterion.CAW0 98/ 1057913It is another object of thean improved communication system02264847 1999-03-02PCTIUS96/14371invention to providewhich will have aneffective range of at least 60 miles which range canbe effectively increased with repeaters if desired.It is another object of thean improved communication systeminvention to providewhich makesavailable an entire range of communicationpossibilities to any structure by the use of simpleplug in devices without the necessity of any furtherconnections.It is another object of thean improved communication systeminvention to providewhich will notrequire the generation of any radio frequency signalsto further clog the already crowded airwaves.It is another object of thean improved communication systemportable and always available.It is another object of thean improved communication systemonly one receiver network/centerstructure.invention to providewhich is trulyinvention to providewhich will requireper receivingCA 02264847 1999-03-02W0 98,105” PCT/US96/1437114Finally, it is a general object of the inventionto provide improved elements and arrangements thereofin an apparatus for the purposes described which isinexpensive, dependable and fully effective inaccomplishing its intended purposes.These and other objects of the present inventionwill become readily apparent upon further review ofthe following specification and drawings.CA 02264847 1999-03-02WO 98/10579 PCT/U S96/ 1437115Brief Description of the Drawing FiguresVarious other objects, features, and attendantadvantages of the present invention will become morefully appreciated as the same becomes betterunderstood when considered in conjunction with theaccompanying drawing, in which like referencecharacters designate the same or similar partsthroughout the view, and wherein:The Figure is a schematic diagram of the overallsystem of the invention. CA 02264847 1999-03-02W0 98/ 10579 PCT/U S96/ 1437116Detailed Description of the Preferred EmbodimentAs shown in the drawing the present inventionconsists of a means of communication between astructure 1 and a remote structure 2 connected to oneanother only by an electric power transmission line100. A transmitter/controller device 10, located atstructure 1, is plugged into an outlet 13 in a wall14 by means of a wire 12. Wire 15 further connectsoutlet 13 to the main structure AC power input box16. Main power line 17 leading from structure 1leads to an existing local transformer 19. Shown at18 is a schematic representation of the signal inline 17. It demonstrates that the signal is made upof a main AC power signal of low frequency (typically60 Hz.) plus a superimposed high frequency, pulsing,or "ripple" signal which has been transmitted bytransmitter 10. The transformer 19 is connected tothe standard power transmission lines 100.On the other end of the power transmission lines30, near structure 2, is an existing power linetransformer 21, such as is normally used to step downthe transmission line voltage from a hightransmission potential to the commonly used 120 volthousehold potential. It should be noted that thesetransformers on both ends of the power transmissionline will do nothing to the superimposed "ripple"CA 02264847 1999-03-02W0 98,105-79 PCT/U S96/ 1437117data signal of this invention except perhapsintroduce a slight phase lag into the signal. Thephase lag will have no effect on the operation of theequipment contemplated as using the communicationsignal to be more fully described later.A "smart" receiver 20 is located in structure 2.The receiver is "smart" in that it is programmed onlyto capture ripple signals on the incoming power linethat have been encoded with a unique destination codewhich matches that of the receiver. All other ripplesignals on incoming power line 22 will be blockedfrom transmission into structure 22 or otherwiserendered ineffective. In this manner signals beingsent to another structure on the power line grid (notshown) cannot enter structure 2 and have nopossibility of interfering in any way with theoperation of any electrical appliances withinstructure 2. However, if a packet of informationidentified as belonging to structure 2 is detected,the receiver will pass through that particular rippleto all the standard electrical wiring outlets 23 inwalls 24 of structure 2. From this point onward theactual control of appliances, such as 25, 26, and 27within structure 2, in accordance with the digitalcontrol signals derived from the ripple signal, iseasy to accomplish. For examples of such control the CA 02264847 2001-04-2318reader is referred to U.S. Patent No. 5,051,720. Forease in making the comparison it is pointed out that“smart” receiver 20 of this invention correspondsroughly to master unit X10 of the incorporated,patent. The major difference between the smartreceiver 20 and master unit X10 would be the additionof conventional pulse blocking or blunting circuitrywhich remains active until a specific user code isdetected. This type of circuit is commonly in usetoday in remote pager units and further descriptionis not believed to be required.The various controlled appliance units 25, 26,and 27 of this invention correspond to the combinedslave units and appliances of the incorporatedpatent. It is contemplated that the slave decodingunits could either be incorporated into the wall plugoutlets of structure 2, incorporated into theappliances themselves, or incorporated into the powercords 28 connecting appliances 25 and 26 or the powercord 29 connecting the alliance 27. Regardless oftheir location the slave units would operate tocontrol their respective appliances in a manner suchas disclosed in the incorporated patent.At least three kinds of control signals arecontemplated by the instant invention and the drawingWO 98110579CA 02264847 1999-03-02PCT/U S96/ 1437119shows a single example of a possible use for each.The simplest is an on off control signal that mightbe used to turn on a light appliance 25 through line28. Another type of signal could be a full fledgeddata string of text or graphics information which isrepresented by wire 29 to computer 26. Finally, acommand control code could be received such asillustrated by signal 30 controlling VCR 27 viastandard VCR remote controller 31. The artisan willrecognize that the possible combinations of thesethree types of data transmission, via electric powerlines, are endless.It is to be understood that the invention hasbeen described, for simplicity only, with referenceto structure 1 being the transmitting structure whilestructure 2 is the receiving structure. Inactuality, both structures would contain combinedtransmit/receive units to make possible two-waycommunication between any two structures on theelectric power grid.A list of reference numerals for the presentinvention follows:1 first structure2 second structureW0 98/ 10579101213141516171819202122232425262728293031100CA 02264847 1999-03-02PCT/US96/1437120encoding transmit unitwire from transmit unit to walloutletwall outlet in first structurewall in first structurewire from wall to AC junction boxAC junction boxwire from junction box to transformerschematic of signal in wire 17main power transformer"smart" receivermain power transformerline from transformer to receiverwall outlets in structure 2wall in structure 2controlled light appliancecontrolled computer appliancecontrolled video recorder applianceon—off control line to lightdata control line to computercommand control signal to VCRVCR remote controllerstandard power transmission linesIt is to be understood that the providedillustrative examples are by no means exhaustive ofthe many possible uses for my invention.W0 98/ 10579CA 02264847 1999-03-02PCT/US96/1437121From the foregoing description, one skilled inthe art can easily ascertain the essentialcharacteristics of this invention and, withoutdeparting from the spirit and scope thereof, can makevarious changes and modifications of the invention toadapt it to various usages and conditions. Forexample, the artisan could easily ascertain that aunique digital pulse code is not the only means bywhich an individual receiver could be activated. Forexample, tones of certain frequency in a certainsequence similar to touch tone telephones could beused. For security, a "ready" acknowledgmentverification at the receiving unit might be requiredbefore the transmitting unit actually delivers themessage unto the line. All current technologicaladvances, such as increased bandwidth and error freecommunication protocols, are to be considered withinthe realm of this invention where applicable. Avariety of other devices that could be controlled inthis manner would also be obvious to the routinist.Some examples are facsimile machines, telephoneanswering machines, and programmable digitalcomputers capable of controlling further appliances.It is to be understood that the presentinvention is not limited to the sole embodimentdescribed above, but encompasses any and allembodiments within the scope of the following claims.

Claims (5)

1. A data communication system using existing electric power transmission lines comprising;
transmitter means at a first site for superimposing on the power transmission lines connected to and providing power to said first site a superimposed ripple signal including a unique identifying portion containing a site destination code;
a second site connected by said power transmission lines, said second site containing a plurality of diverse electrical devices with local wiring connected to and operated by the electrical power delivered by said transmission lines;
receiver means at said second site interposed between said transmission lines and said local wiring for passing said electrical power from said transmitting lines to said local wiring, said receiver means being responsive to said site destination code for passing said superimposed ripple signal containing said site destination code through to said local wiring and all of said electrical devices in said second site when said unique identifying portion is present and for blocking any ripple signal when said unique site destination code is absent to avoid any interference by said ripple signal with the operation of any electrical device in said second site; and control means operatively coupled to said local wiring in said second site so as to control electrical devices that are plugged into said wiring, in accordance with said superimposed signal passed through by said receiver means.

2. The data communication system of claim 1, wherein;
said superimposed signal further includes an encoded portion capable of causing said control means to turn on and off the power to one of said appliances.

3. The data communication system of claim 2, wherein;
said superimposed signal further includes an encoded portion capable of causing said control means to further transmit command control sequences to cause remote operation of one of said appliances.

4. The data communication system of claim 3, wherein;
said superimposed signal further includes an encoded portion capable of causing said control means to further transmit and store data on one of said appliances.

5. The data communication system of claim 1, wherein;
one of said appliances is a programmable digital computer and said superimposed signal is capable of initiating a program stored in said computer, wherein said program is capable of causing said computer to send its own secondary control signals to other appliances so as to further control the operation of said other appliances.