WO2003071708A1

WO2003071708A1 - A communications system utilising electricity cabling

Info

Publication number: WO2003071708A1
Application number: PCT/NZ2003/000022
Authority: WO
Inventors: John Gordon Rutherford
Original assignee: Rutherford J G
Priority date: 2002-02-21
Filing date: 2003-02-12
Publication date: 2003-08-28
Also published as: NZ517321A; AU2003210081A1

Abstract

A communication system receiving and transmitting signals form and to remote communications sources and serving the proximate community from an unmanned cellular processing point utilising alternating current electrical cabling supplying electricity to end user premises in the low voltages from electricity grids conventional for domestic, commercial and industrial use, and conveying digital or analogue communications data to electricity outlets of said end users; said system including specialised end user equipment and facilities for modulation, multiplexing, channeling, coding and other communications, switching, security, filtering, display, and storage techniques with capability of interfacing with an electricity utility for the purposes of network management, meter reading and billing. Said system further enabling linkage to other low voltage alternating current circuits for communications that include telephone service, electronic commerce, video and Internet data.

Description

A COMfvIUNICATIONS SYSTEM UTILISING ELECTRICITY CABLING

The invention relates to the need to transmit cost effective broadband communications services the "last mile" to end users utilising infrastructure and equipment that are existing or affordable in developing countries, in homes, offices, educational and similar institutions, by utilising electricity cabling within and near commercial, institutional, community and domestic buildings.

New Zealand Patent 235810 Australian Patent 642110 and UK Patent GB2278254B (Rutherford) addressed this need a decade ago and the invention described therein has been utilised in the low cost transmission of multiple channels of television from cellular points to proximate communities without the need to add wires to poles or dig up the streets for broadband cabling. The present invention develops the theme of this prior art by more extensive use of the electricity cabling referred to in those patents, which is already in place in most communities. Such is in contrast to the cost and inconvenience of installing new equipment (such as Digital Subscriber Line) designed to upgrade the narrowband twisted pair telephone cabling that also exists within the homes and commercial buildings in most places. The cabling carrying the electricity to end users is more robust and capable of providing a wide range of communications services with the addition of appropriate modems and other equipment at cellular processing points close to end users, as is the theme of the patents referred to above.

The cellular processing point referred to above is connected to the low voltage electricity grid which carries alternating current below 500 volts, may be located at the transformer point which converts mediuή voltage electricity as conveyed from substations more directly related to generating plant, to the alternating current as used in the homes and businesses, by appliances manufactured for use with 1 lOvolts - 230volts A.C., as prevails in most countries.

Such transformers in metropolitan locations are conventionally connected to between 100 and 200 end users in domestic premises utilising cabling to provide connectivity for single phase appliances at 230 volts of alternating current (A.C.). While lesser numbers are connected to 110 volt systems, the ability to spread the cost of processing equipment across many users on the same low voltage electrical circuit is a very cost effective system. Such can be contrasted with the many computer users having an individual satellite terminal and receive card (for example, Broadlogic cards) in each computer to enable high speed Internet data to be delivered direct from satellite. Only one such Broadlogic or similar processing card would be required in the equipment installed at the cellular processing point to serve many users, and the same applies to one shared dish at each cell site as is referred to in the above described patents.

The cellular processing point introduces the data from a communications source that is preferably a broadband source such as fibreoptic or coaxial cabling, terrestrial wireless or satellite downlink to a receiving satellite terminal which may also include a transmit capability to return the signals to the satellite and provide a duplex mode. The prerequisite is a "clean" signal presented as close as possible to the end users' low voltage powerlines, which due to attenuation, impedance issues and external potential for interference need careful "conditioning" to effectively carry a transmission of voice data or video to end user appliances with good signal to noise ratio (SNR)

At the cellular point processing similar to that described in the above patents can take place but with the addition of a modem and related equipment designed to transmit the data to and from the cell site along the electricity cabling at frequencies that will not conflict or dreate interference with the characteristics of the electricity transmissions or ahy control systems present on those cables as imposed by the electricity utility for signalling, and purposes such as "ripple" control for the turning on and off of electrical services for water heating or similar applications.

Broadband communications transmissions are frequently compressed in the interest of conserving available bandwidth and decompression in such circumstances may either take place at the cellular processing point in association with the modem or at the end user outlet or outlets with corresponding modems connected to computers, television sets and the like. In particular the compression format known as MPEG4 is particularly suited to use with the invention as it is very conservative of the bandwidth transmitted along the electricity cabling that connects to multiple electrical outlets in homes and offices and can accordingly be used for multiple connections to computers and the like to provide an Ethernet style of connectivity without the need to lay new communications cabling for such broadband services.

The existing state of the powerline communications (PLC) art, is that it has been used for conveying Internet data injected from sources such as fϊbreoptic cabling from the servers of Internet Service Providers (ISPs) at low voltage transformers or at medium voltage substations, and carried on the medium voltage lines to low voltage transformer points and thence via the low voltage transformers to a gateway facility at the meter box or similar incoming point where the external electricity grid meets the end user's in-building electricity wiring. At that incoming point an access device processes the incoming signals for receipt at the power outlets in the individual building rooms where a modem is plugged in and relays the signals to an individual computer or similar device. Extension modems are available for plugging in to other power outlets in the same building to relay the signals to another computer or similar device for networking purposes. This format presents difficulties with interference both emanating from the powe lines and transformers and from other devices radiating radio frequencies in the vicinity of the transmissions which degrade the signals and limit the desired propagation to multiple users in the interests of minimising transmission and equipment costs.

The cross bar configuration and other metal parts and conductors within low voltage transformer creates an antenna effect that causes adverse reaction on the PLC transmissions and where a transformer is used as a relay point for the broadband transmissions which have come to that transformer on the medium voltage lines, it is desirable to bridge over that transformer with an independent voltage divider with appropriate capacitors and filters to avoid the above problems that the transformer will create. A preferable course is to take the data off the medium voltage line at a point removed from the transformer by a coupler that is independent of it but performs a similar function with shielded conductors and other radiation suppressing characteristics.

The method of introducing communications transmissions at an unmanned cellular processing point, as referred to in the above patents, centrally in the proximate community to be served has relevance in the present invention which is a derivation of that concept.

Accordingly a preferred method of implementing the invention is to have the PLC processing point where the "clean" data is introduced in a position that avoids the transmission path on the powerlines commencing at one end of the low voltage circuit that supplies multiple apartments, homes, offices, a school campus or similar, but rather centrally so that the transmission length in any direction from said cellular processing poin}: is minimised. The low voltage transformer is at the entry point of the circuit and generally a low voltage line extends linearly down a street until such point as it teπninates due to line loss. By way of example, such distance may be 400metres and a preferable course is to inject the data at the 200 metre point so that the distance it travels in both directions is 200 metres and this is distance within which the SNR is satisfactory without the use of repeating amplifiers. Accordingly, to implement this method it is desirable to introduce the data remote from the transformer either into the ground floor level of a building where the feed is brought in by fibre or coaxial cable or on the roof of a building where the feed is by terrestrial wireless or satellite delivery to a satellite receiver and related equipment as depicted in the drawings submitted herewith.. In such case the modem and capacitors required to condition the data for digital transmission on the powerlines can be built in to the control unit/receiver/transmitter in the case of receipt of wireless signals, or into the control unit/cable converter in the case of signals coming in by coaxial cable, or into the control unit/opti- electronic coupler in the case of signals coming in from a fibre line. Where the signals are compressed signals by MPEG compression or similar, the decompression can take place either at the point where the first receiver in a building carries out the decompression or at individual TV set-tops, or by computer cards in individual homes or apartments so that after receipt at the cellular processing point, the data flows out through the first building and into the external grid to serve all other end users on the same low voltage circuit, and ultimately stops at the low voltage transformer.

One method of minimising radiation and interference within a building is to inject the data in manner referred to above on to the neutral and earth conductors that conventionally travel to every power outlet in the walls of a building and leave the phase wire and the frequencies it carries at 50 - 60Hz, independent of the conductors that become the communications carriers.

It is further desirable to use radio frequencies well away from the above alternating current frequencies and also the frequencies used by the electricity utility for network management and "ripple" control such as are in the kHz bands. Instead, the bands between 1 -10MHz for outdoor use on the electricity grids and 11 MHz upwards to approximately 50MHz for in building use are satisfactory transmission media not utilised by other services in most countries and therefore interference is minimised and the electromagnetic qualities are advantageous to good reception by end users. Due to the various attenuating factors that adversely affect powerlines, it is desirable to distribute the PLC transmissions over numerous sub channels with gaps between them, in the preferred frequency ranges referred to above. Accordingly choosing a modulation system appropriate to this concept is necessary and quadrature amplitude modulation is a preferred modulation system (QAM). To utilise an optimal reception technique of frequency hopping, Orthogonal Frequency Division Multiplexing (OFDM) as used in Digital Audio Broadcasting (DAB) and asymmetrical digital subscriber line (ADSL) or similar multiple access transmission methods are preferred.

It is a preferred application of the invention that the modems, filters, capacitors and any other elements of the end user equipment necessitated by the characteristics of the powerlines carrying the transmissions, be built in to the receivers, transmitters, computers, TV sets or TV set-tops, especially where compressed signals are received, so that an environment appropriate for conditional access for Internet data management by ISPs, Pay TV signals for such content providers, and similar services, are all within a unit that enables commercial management of the data and also provides security, and minimises radiation either from the devices or incoming from external sources.

Prior art has had PLC equipment at "gateways" at meter boxes and/or on transformers without the benefits of shielding, compression or decompression, security, or the range of communications capabilities of the cellular processing points that are a significant feature of the present invention, as is the concept of building in the PLC modem and related equipment to end user devices, in the interests of maximising performance, saving cost, for convenience, and portability. An extension of the concept of building in the PLC reception and transmission capability to the end user computer, TV set, and similar is, the concept of also building such capability into "smart" home appliances so as to enable remote control of such devices, or self regulation of them, to predetermined criteria. By so building in the consumer PLC processing equipment to the appliances that utilise it, and doing the same at the cellular receive/transmit points and then utilising cabling in the buildings that is neutral and earth rather than phase, which leaves the frequencies on the phase cabling unaffected, reception should be in the vicinity of SNR of 60dB in the 10 -30 MHz range and enable theoretical transmission speeds approximating 200Mbps. Such capabilities will always be subject to local factors applicable at individual locations as related to external interference and radiation from broadcast signals and other emissions in the vicinity.

It is a preferred embodiment of the invention that the PLC control unit be built into the cellular processing point and that reciprocal control units in end user appliances and equipment are likewise built in or included as accessories that can be inserted as a card in a computer or similar so that the characteristics of the appliance, TV set, computer, Personal Digital Assistant (PDA) or cell phone are preconditioned for use with PLC transmissions. In this manner, signal levels at the end user equipment will be maximised, interference and unwanted emissions will be minimised, and such can be achieved by the items referred to in the previous paragraph and also by shielding in the case or other items in the end user equipment. Such also is beneficial for reasons of portability and security.

The optimum configuration for the modems at the cellular points and the end user appliances or power outlets at the wall plugs will vary to some extent with circumstances and regulations locally applying but one such configuration applicable to the invention would include microprocessor means, lowpags filters and amplifier, automatic gain control, analogue to digital, and digital to analogue converters, signal synthesiser, symbol processing unit for multi- carrier technology, capacitors and a balun to match the characteristic impedance of the powerline cable to be utilised and "condition" it for maximum transmission efficiency. Such items are hereafter collectively, (or jointly or severally as required) referred to as the "control unit". The above aspect of the invention that relates to building the Control Units that provide the interface to the power lines into the end user appliances is a very significant advance on the existing state of the art as it relates to external and independent modems that exist on transformers, at "gateways" into buildings and otherwise plugged into wall sockets as such are more exposed to undesirable emissions, radiation, and interference for broadcast radio signals and similar. Recent advances in polymer composites by researchers such as Professor Alan MacDiarmid, Nobel Prize winner in chemistry in the year 2000 for his work in this respect, provide the opportunity to make cases for TV sets, computers, keyboards, cell phones, home appliances, and the like from polymer composites that either have dielectric or conducting qualities and more particularly can be tailored to conduct at preselected radio frequencies, or to block undesired frequencies. In new buildings such polymer composites can be utilised to advantage in PLC transmissions and can be retro-fitted into older buildings where shielding is needed in areas of exceptional interference. Such polymer composites can equally be used to advantage in the cellular processing points as are part of this invention.

It is a further aspect of the invention to include in the transmission and reception capability in the frequency range of 1 - 50MHz, equipment to automatically read electricity meters (AMR) and relay the data back to the end user and either at those frequencies or other lower frequencies, to the service provider, initially on the power lines and thence via the wireless or cable lines that bring in the communications services to the cellular processing points, so that the details of the meter reading and the billing therefor can be provided both to the end user via a TV, computer or similar appliance, and also to a concentrator (or storage device) or directly to the processing office of the electricity utility. Such enables demand side management, which is the ability of the end user to have greater control over his electricity costs. It also enables him to have individuaUy structured pricing with his electricity supplier that could for example, enable a monthly charge of a set figure that the utility could average in relation to use over winter and summer, peak or low demand periods, and so enable a monthly or other periodic averaged payment to be taken by electronic funds transfer from the end user's bank account via PLC transmission and thereby avoid the cost to the utility of monthly billing with the ability to warn the end user via his TV set or computer if limits are being exceeded, or control appliances by "ripple' control or similar to ensure the automatic payments being taken from the end user's bank account relate to the electricity usage. Accordingly by reading meters on an hourly or other frequent interval, theft by consumers, or graft by meter readers, is avoided; targeted pricing and usage structures can be instituted, with resultant efficiencies, conservation, and lower cost billing.

It is a further feature of the invention that enables the building in at the cellular processing point of storage capability for data that can be utilised by the end users on the low voltage circuit that the cellular processing point supplies to perhaps 200 customers in a suburban block of low rise individual homes or more than double that number in a high-rise building of small apartments, Using the compression technologies of the Motion Picture Experts Group (MPEG) or similar, movies can be downloaded to the cellular point at night or other off peak time and drawn upon by end users later, so as to provide a video on demand service and minimise transport of such items over longer distances. Such can be delivered in this manner by local suburban video stores instead of the need to uplift and return video tapes as is the current method of providing movies for home entertainment. Digital delivery of movies to cinema servers as is a recently developing technology can be extended by transmitting late release movies from theatres to homes in a controlled way that ensures payment, (by recording at the cellular processing points, by passwords or otherwise) and respect for copyrights, with delivery to end users via PLC

In the same manner as video services can be cheaply made available to the proximate community on the same low voltage grid, and such might comprise 2-400 end users that include suburban shops, educational, medical and dental services, and other community facilities it is a feature of the invention that telephone service by means of Voice Over Internet Protocol can be used by said community members with telephones that are independent of the Public Switched Network (PSTN) and accordingly telco charges can be avoided within the community with no charges for local calls, line rentals or other imposts that are conventional for telephone service from telcos. Monitoring of medical condition of patients in their homes and other community services can be achieved by this method..

While the proximate community referred to herein can be linked to many other such communities served by low voltage circuits, via the medium voltage powerlines which can carry PLC transmissions for many kilometres, an alternative is to link the cellular processing points in each low voltage circuit/community by terrestrial point to point or point to multi-points by terrestrial radio transmissions, and such is another feature of the invention whereby metropolitan suburbs can be linked or a series of small rural communities. Currently the couplers used to bridge data from medium voltage powerlines on to low voltage grids and vice versa are relatively expensive where the number of end users in the low voltage grid is small and the spread of cost is limited, because the voltage division required from thousands of volts on medium voltage lines requires substantial transformers, capacitors and the like, and pending the lowering of costs with mass production or advances in present technology, linking the cellular processing points that are a major feature of the invention, by wireless means is cost effective, especially if a little used band from 12.75- 13.25GHz, above the Ku Band satellite downlinks is used. This band is referred to in the United States as the CARS (Cable Assisted Relay Service) Band as its use was restricted to linking TV cable hubs by microwave but now such hubs are generally linked by fϊbreoptic cable due to the greater number of TV channels required in that market in recent years. This circumstance has resulted in CARS Band transmitters being redundant in the US and available at low cost, and recycled into other markets. Linking cellular processing points serving low voltage circuits/communities, by satellite using Very Small Aperture Satellite terminals is another embodiment of the invention and of particular merit where the content to be delivered is Internet data. As much of the Internet data originates in North America, such can be delivered from that source, by satellite direct to one or more cellular processing points and thence via the low voltage circuits by PLC to end users. Such direct delivery avoids the use of undersea cables that are favoured by the undersea cable consortia, generally comprised of telcos. Such undersea cables generally teπninate at one point only in each country and further line charges are involved for in country delivery to end users. In the case of international transmissions, a direct link by satellite from the service provider in one country to the end user connected to a cellular processing point in his immediate community, offers security, speed, and capacity for multiple transactions and content.

Where the cellular processing points are at educational and medical institutions, courses and medical care can be delivered via PLC to those requiring same at home, within the same low voltage grid or linked grids as referred to above.

It is a further aspect of the invention to include at the cellular processing point, security monitoring processing so that sensors plugged into power outlets in individual, homes, apartments, offices and the like can sense and report movements by burglars in a cost effective manner with the data being passed on from the cellular point to security agencies or building management.

An alternative and additional embodiment of the invention is the inclusion of a wireless transmission capability such as the use of infrared transmission, Bluetooth, 802.11 derivatives, and the like, into a modem which is then incorporated in an alpha-numeric QWERTY or similar keyboard used for controlling a computer or television set or TV set-top box similar to a remote control fur such an item whereby data that is taken off the powerlines in manner referred to above, is accessed by said keyboard or remote control and input of new data provided by the user for re-transmission back down the powerlines to service providers. Such portable keyboard-modems can be personalised to the user for security purposes by passwords, digital signatures or other security measures common to the security industry. This format enables the keyboard to be taken to school by a pupil and used in association with a computer, TV set or other monitor, and education materials transmitted between school and home, or similar itinerant uses for business, health and security monitoring, remote payment systems and appliance control, wherever the powerline access is available. Such creates an infrastructure whereby after PLC connectivity, data is relayed by conventional long distance transmission systems to service and goods providers, nationally or internationally, via satellite or otherwise.

One preferred form of the invention will now be described with reference to the accompanying drawings of which:- Figure 1 shows how PLC can be included in a transborder, transoceanic satellite and terrestrial transmission system of which the broadcast transmission (1) from a terrestrial broadcaster in a foreign country or a domestic satellite serving that foreign country (2) is received by an uplink facility (3) with such uplink facility possibly being in a third country and at that point the signal is converted to a form appropriate to uplinking and downlinking on a satellite (4) with international beam coverage of other countries which include a country of downlink (5) where the downlinked transmission is received either at an intermediary terrestrial station on a hilltop or tall building (6) for retransmission in similar form (7) to a PLC cellular processing point (8) or alternatively in the event of a high-powered DBS transmission (9) downlinked directly to said cellular processing point ( which may be either free standing or on or in a building) and there reprocessed by downconversion, decompression, encoding, decoding, addressing, interdiction, remodulation, or otherwise prepared for transmission down powerline cables in a low voltage electricity grid (10) and thence in to buildings also on electricity cabling to end users in form appropriate to reception by television sets, computers, and other appliances. On the return path from the end user, his response transmission is back down the electricity cabling (10) to the cellular processing point and thence uplinked direct to satellite (usually a domestic or regional satellite) (13) by a Very Small Aperture Terminal (VSAT) link, or transmitted by microwave to a remote cellular processing point serving another proximate coimnumiy connected to a low voltage grid, or as a further alternative, transmitted via a telephone wired or wireless link into the switched telephone network, for transmission to the service provider or advertiser.

Material going into the uplink can either be simultaneously uplinked to transborder, transoceanic satellites in "real time" or otherwise recorded and transmitted as transponder capacity is available for non-urgent delivery. The transoceanic transmission on an Intelsat or similar satellite for reception in western Pacific countries such as New Zealand will normally be in C-Band or possibly Ku-Band with the downlinking of such material, should it be a C- Band transmission, most likely received at an intermediary terrestrial station on a hilltop site in (for example) Christchurch, New Zealand, utilising a dish of a size capable of receiving this transmission in a quality appropriate for terrestrial retransmission, with such retransmission being in the same or similar SHF frequencies, to a multitude of cellular processing points, that would generally be within a few hundred metres of the end user's receiving equipment. Downconversion of the SHF frequencies to the frequencies acceptable to the consumer's equipment (TV set, VCR, computer and the like) would take place at the cellular processing point, located in metropolitan areas, one to each low voltage grid, in close proximity to the end users, typically in each city or suburban block that is bounded by streets and serves the proximate community from a central and inconspicuous position or in or on a building, without the need to lay cables crossing streets. Cabling in streets, either on poles or underground is disruptive, visually unattractive, and increasingly opposed by local authorities having jurisdiction over the streets.

Figure 2 is a schematic showing typical processing units involved in the community communications system at the cellular processing point in one or more enclosures or in a plant room of a building, and in the premises of one of the end users. The schematic shows the optimum features of a cellular processing point and in practice, the connectivity to long distance transmission systems may be a lesser number of alternatives such as only by the electricity cabling on medium voltage lines to remote communications services, or any combination of those shown collectively in Figure 2. Similarly the internal processing equipment shown in the schematic is indicative of a range of services that may be marketable to end users but such will vary with the demographics of said end users and relate to alternative services that may have been previously established in any community and therefor be unnecessary for inclusion in the services possible at the cellular processing point.

As with Figure 1, No 7 in Figure 2 depicts the incoming terrestrial SHF microwave signals via an antenna at said cellular processing point. No 9 and No. 13 are the incoming and outgoing satellite signals via the satellite antenna or antennas and No. 11 represents the transmit and/or receive RF antennas for voice and data signals. No 12 is representative of the cellular telephone transmit and receive antenna and No. 14 depicts the incoming broadcast VHF/UHF/FM/AM signals on one or more receive antennas. No. 10 and No. 15 are incoming and outgoing cables of broadband capability coming to the community processing point with these being conventionally coaxial or fiberoptic cables. No 16 represents the electricity cabling carrying the PLC signals to end user premises and equipment. One such connection would be made to the electricity meter of an end user for time of use recording, meter reading, and similar data communications for electricity network and demand side management purposes.

No. 20 represents the VHF/UHF/FM/AM broadcast reception subsystem comprising band separation, balancing, channel conversion, and modulation prior to delivery to the launch amplifiers (No. 31). Any required addressable switching, filtering, and trapping devices (No. 33 as described in more detail hereafter) can also be included and connected to the end user premises (No 35) in which are located communications equipment such as a television set (No. 36) an audio stereo receiver (No. 37) telephone (No. 38) (with multiplex to the incoming cable No. 39 connected to the control unit), and a computer (No. 40). These items are also connected to the control unit (No 41) which has both a direct connection to the low voltage electricity grid serving the proximate community (No 16) and the electricity meter (No 42) to enable the meter reading, billing and other energy detail of interest to the end user to be viewed on TV or computer.

The control unit (No 41) in addition to connecting the above specified communications items to the data on the electricity cabling may optionally include portable battery operated communications equipment such as laptop computers, Personal Digital Assistants, and cell phones, by including in the control unit, not only those of the capacitors, filters, automatic gain control, analogue to digital, and digital to analogue converters, signal synthesiser, symbol processing unit for multicarrier technology, for the modems and like items to match the impedance of the powerline cable and "condition" it for maximum transmission efficiency, but also Bluetooth, 802.11 or other short range wireless technology to enable the above items to connect with the data on the powerlines in the walls of the building without plugging in to the power outlets.

In addition to the communications items listed in the preceding paragraph, the control unit (No 41) may also provide and interface for "smart" home appliances and security monitoring. Power outlets remote from the control unit in a building can connect back via the powerlines, security monitoring devices with sensors that transmit, either via a built in modem or one otherwise connected to the power outlet, back through the control unit to security monitoring sources. Similarly Jipme appliances for heating, cooking, washing, and the like can be remotely controlled, preferably via built in modems reacting with counterparts in the control unit or by remote control from distant input sources. No. 21 represents the incoming microwave processing subsystem comprising down conversion to VHF/UHF and modulation to AM for TV set use or digital or other appropriate format for storing or processing to make the signals suitable for accessing by existing telephones, television sets, and similar equipment, without further processing and tuning electronics at end user premises.

No. 22 depicts the incoming satellite transmission subsystem comprising downconverters, receivers, and modulation to the appropriate TV, audio, or data format, and No. 23 is representative of incoming optical services via fiberoptic cable and the optical to electrical and return electrical to optical subsystem to handle incoming and outgoing signals transmitted on the fiberoptic cables (No. 9) connected to this conversion subsystem. No. 24 depicts the trunk interface with the PSTN comprising telephone switch or similar processing facility to take telephony services from the end user premises via the cellular processing point and transmit the same via electricity or other cable, or radio frequency transmission by the subsystems in Figure 2.

No. 25 is the RF transmitter/receiver for terrestrial RF transmissions, to and from the community processing system, and No. 26 is the V-Sat link transceiver for incoming and outgoing signals to satellite transponders.

No. 27 is the cellular telephone base station for reception of the wireless transmissions of cell phones in the vicinity of the end user premises (No. 35) with such cellular base station either being connected to the wireless transmit system or the broadband or fiberoptic cable system connected to the Public Switched Telephone network (PSTN) or similar cellular switching central office. Cell phones with much less transmit power than is required to transmit to remote repeater sites can be used to connect a short distance to the electricity cabling in the proximate low voltage grid and in walls of a building (No 16) and such would have lower emissions which will be attractive to those concerned with higher power transmitters being held against their ears. It is a feature of the invention that cell phones interfacing with service on nearby electricity cabling could either have low power transmit emissions or the capability of switching to low power when used where PLC services are available.

No. 28 is a bank of processors and memory devices for both compressed digital storage and (after processor conversion) analog storage for calling up by the end user's telephone key pads and use by their TV sets, such comprising optical, or similar storage which is linked to No. 29, a bank of decompressors, error correctors, and enhancers, appropriate to decompressing incoming compressed digital signals and converting the same to analog for reception by television and similar analog equipment in the end user premises whilst the decoders in the same subsystem, similarly decode encoded signals in preparation for distribution in receivable form to the equipment of the end user. Such decompression and decoding subsystem is connected to the modulators (No. 30) that format the signals onto the desired channels prior to transmission through the launch amplifiers (No. 31) with such having return path capability, where necessary, for distributing signals originating in the end user premises which where appropriate, pass through the encoding, queuing, and polling system (No. 34) to the various outgoing transmission systems referred to above. Such subsystems and processors will be included in individual cellular processing points as appropriate to the demographics of the end users and the requirements of regulators and government agencies, which in the case of the Global Positioning System (GPS), polling and time recording capabilities, can derive benefits from cheaper referenda, remote health care, distance learning, security monitoring and other public benefit services.

No. 32 is the power supply unit to power the DC subsystems in the said electronics enclosure and such would conventionally be supplied from an electricity connection to one of the end user premises but with solar and/or battery back-up.

No. 33 represents the switching subsystem for directing incoming and outgoing signals through the cellular processing point to and from the appropriate subsystems therein. Such includes the capability for subscriber management of Pay TV systems where the switchable interdiction system addressed from a remote control point or headend can supply or deny signals on a selective basis sent to end user premises. Conversely, the switching system will pass signals from end users, initiated by telephone keypads or personal computers, to service providers directly, or store said signals for later polling and retrieval in the encoding and queuing subsystem where, if appropriate, signals can be encoded for security or other reasons. Such signals can be queued by recording them on a time received basis to enable service providers to classify time sensitive material.

No. 43 is a telemetry control system for activating and monitoring remote GPS devices on end user vehicle and similar mobile equipment, or locating elicit equipment.

The word "Multiplex" as appears in Figure 2 at the end user premises (No.35) refers to multiplexing a telephone on to the building's electricity cabling. The words "Control Unit" (No 41) in said premises, in addition to the features referred to above will incorporate such modulation, multiplexing, channelling, signalling and other communications, security, switching, filtering, display, and storage techniques as are appropriate for the processing of the varying types of incoming and outgoing data on electricity cabling as required by each end user. Such techniques are more relevant to the carriage of communications on electricity cabling than for purpose built communications systems where shielding and regulatory protection assist in assuring interference free transmissions. Accordingly, said techniques must take account of electromagnetic and other local and remote potential interference sources that may limit propagation and cause attenuation of signals hence the earlier reference to QAM modulation (on page 7) and the preference for multiple access transmission systems and wireless interfaces using short range transmissions at radio frequencies well removed from alternating current frequencies. Communications used for managing the electricity network require different symbol rate frequencies and carrier means to avoid interference with other traffic on the system and (for example) enable meter reading data in SCADA or other format to be displayed on the end user's TV or computer monitor. Further carrier means can enable electricity billing and usage data and other data to be cost effectively delivered, scanned, and/or printed out by said end user by wired, networked or wireless means.

In particular the invention:

(1) Creates an extremely low cost method of delivering high quality Internet data, video, and voice services from a central processing point within or near buildings on each low voltage electricity circuit providing alternating current to proximate consumers, to secondary (receiving) sites in duplex mode;

(2) Can substitute data and data formats such as Internet for television programming where required and can also provide telephony;

(3) Can deliver the information to digital or analogue appliances as required by the user of the system and the parameters of the system;

(4) Can deliver the information data by multicasting to all reception points or to selected receiving sites using low cost conditional access, encryption and/or firewall systems;

(5) Provides a transmission in frequencies acceptable to the International Telecommunications Union (ITU) without creating interference with electrical or communications equipment in the vicinity of the service., and creates much cheaper and more reliable services than wireless systems that use spread spectrum in unlicensed bands, or microwave transmissions that require line of sight conditions.

(6) Utilises existing cabling within the end user premises that is more robust than the traditional copper pairs used for telephone service and which is generally already approved to a high standard of safety for electrical purposes. Such can be amended between the low voltage transformer and the end user premises as required by linesmen already approved by electrical authorities, in contrast to the installation of wireless systems requiring expertise in broadcasting by microwave transmission;

(7) Within a geographic area enables numerous totally independent, non- aligned and not-cooperative users to co-exist with simultaneous use of the same communications transmission system, yet not present any objectionable level of interference between co-existing systems in the same geographic region (something only possible at microwave frequencies because of the use of shaped and controlled radiation beams and polarisation offsets);

(8) Avoids the cost, disruption and environmental problems associated with laying new communications cabling in streets and other public places and negates the concerns felt by some in respect to increasing radio emissions from long range wireless devices.

(9) Maximises system coverage by utilising existing infrastructure that already penetrates man made objects (building walls), natural barriers (hills, mountains, trees) in contrast to the line of sight problems encountered by microwave transmission

(10) Creates a transmission - reception system which is as impervious to human mistake and installation error as is possible with current technology, thereby reducing the level of skiU required to install and operate the system, where the additions to the existing cable reticulation are mainly of a "plug and play" nature

(11) Avoids the need to overlay existing cabling in buildings with new wiring to create communications networks.

(12) Utilises existing electrical outlets and plugs that are already connected to end user computers and similar appliances for delivering the electricity to those items.

(13) Enables the use of very low power wireless transmission devices (such as Bluetooth or FM transmissions with milliwatts of power) to connect end user equipment wirelessly to the electricity cabling system in buildings without the interference potential endemic in longer range wireless transmissions.

(14) Spreads the cost of transmitting EP and similar data amongst many users on cabling that in most cases has been installed many years ago at lower cost than current alternatives, and thereby assures speed of deployment without disruption to existing structures or the environment.

(15) When the transmit/receive modems and related PLC processing equipment are built into equipment such as keyboards, computers, set-top boxes, remote controls, and appliances, enables a degree of portability, flexibility convenience arid security in a very cost effective manner.

(16) Avoids the need for the installation of Ethernet cabling to carry broadband communications services within buildings.

(17) Enables transmission of telephone services in Voice Over Internet Protocol (VOIP)

Claims

WHAT I CLAIM IS:

1. A communications system serving the proximate community from an unmanned cellular processing point utilising alternating current electrical cabling supplying electricity to end user premises in the low voltages from electricity grids conventional for domestic, commercial, and industrial use and conveying communications data to electricity outlets of said end users, said system receiving and transmitting signals from and to remote communications sources and including

(a) end user equipment for receiving and returning such signals to said cellular processing point and other points on the said low voltage electricity cabling;

(b) facilities converting digital transmissions to analogue transmissions and vice versa;

(c) facilities for filtering out unwanted interfering emissions;

(d) facilities for minimising attenuation of the commumcations signals on electricity cables;

(e) facilities for error correcting transmissions;

(f) facilities for modulating the signals on to said electricity cables in a manner that divides the available spectrum into sub-channels;

(g) facilities for processing and on-forwarding of data on electricity cabling.

2. A communications system as claimed in claim 1, where the transmitted signals comprise Internet data transmitted to and from end users to said cellular processing point and thence for delivery via cable or wireless means to Internet data sources.

3. A communications system as claimed in claim 1, where the transmitted signals are television programming transmitted in compressed or uncompressed format to end user television sets or computers.

4. A communications system as claimed in claim 1, where the transmitted signals are telephone services in Voice Over Internet Protocol (VOIP)

5. A communications system as claimed in claim 4 where said telephone services extend over one or more low voltage grids and serve the communities connected to such grids independently of the public switched network of a telephone company.

6. A communications system as claimed in claim 4 where the cellular processing point serving one low voltage grid is connected by wireless means o the cellular processing point in another low voltage grid or to multiple such grids to serve the communities within such grids.

7. A commumcations system as claimed in claim 1 where the transmitted signals are for the purpose of electronic funds transfer.

8. A commumcations system as claimed in claim 1, whereby the signals received at and transmitted from the cellular processing point are satellite signals

9. A communications system as claimed in claim 1, whereby the signals received at and transmitted from the cellular processing point are connected by fibre optic cabling to remote communication sources.

10. A communications system as claimed in claim 1, whereby the signals received at and transmitted from the cellular processing point are connected by medium voltage electricity cabling to remote communication sources.

11. A communications system as claimed in claim 1, whereby the signals received at and transmitted from the cellular processing point are terrestrial wireless signals from remote sources.

12. A communications system as claimed in claim 1, whereby the signals received at and transmitted from the cellular processing point are signals received by a television or computer monitor and are interactively dealt with by a wireless keyboard with built in powerline communications modem enabling interaction by an end user with incoming signals from the cellular processing point.

13. A communications system as claimed in claim 1, whereby the signals are received by sensors connected to power outlets in buildings that are for the purpose of securify monitoring and are conveyed to the cellular processing point on the electricity cabling for on-forwarding to security firms.

14. A communications system as claimed in claim 1, whereby the end user devices have wireless transmission capability for connectivity to and from battery operated equipment in the form of laptop computers, personal digital assistants (PDAs), data logging or reading equipment, and cell phones to enable such devices to connect with the data on the electricity cabling in the walls of buildings without plugging in to power outlets.

15. A communications system as claimed in claim 1, whereby compressed television signals are decompressed at either the cellular processing point or at the end user equipment points in the form of TV set-top boxes with conditional access facilities or computers with like facilities.

16. A communications system as claimed in claim 1, whereby said cellular processing point has storage capabilities that enables storage of incoming movies in compressed form downloaded and stored for use by end user equipment via said powerlines at a later time.

17. A commumcations system as claimed in claim 1 whereby storage and queueing facilities at said cellular processing point enable interactive responses of end users to be polled by remote means for enabling participation in referenda, game shows, educational courses, betting or similar interactive use via the powerlines.

18. A communications system as claimed in any preceding claim, whereby the frequency band for the receipt and transmission of data on electricity cabling is 1 - 50MHz.

19. A communications system as claimed in claim 18, whereby electricity meter reading (AMR) equipment is activated so as to read meters supplying electricity to end users by means of said frequency band or any part thereof.

20. A communications system as claimed in claim 1 whereby electricity meter reading and billing of the electricity consumption so ascertained is displayed on end user TV or computer screens via said electricity cabling.

21. A communications system as claimed in claim 1 where an end user by a computer, television set or telephone can implement demand side management and adjust use of electricity and make payment for same by the interface created between electricity meter reading via power lines and the connectivity to end user control and/or payment equipment

22. A commumcations system as claimed in any previous claim where the transmitted signals are duplex audio, video, or graphics signals

23. A communications system as claimed in any preceding claim where the data transmitted is secured from intervention or interception by an encryption and error correction technology that also offers a handshaking capacity to ensure previously identified parties are correctly linked and in the case of a financial transfer that such takes place between the appropriate parties securely and free from errors.

24. A commumcations system as in any preceding claim where data signalling information incorporates one or any combination of the following modulation, multiplexing, channelling and other commumcations, security, switching, filtering, display, and storage techniques:

(a) Packetised multiplexing;

(b) Time division multiplexing;

(c) Frequency division multiplexing;

(d) Code division multiplexing

(e) Two or more carrier means;

(f) Separate carriers for carrying data to and from and end user;

(g) More than one data channel being modulated onto each carrier, to enable multiple connections to end user communications equipment;

(h) Carrier and digital symbol rate frequencies being determined in manner not to interfere with other traffic on said communications system;

(i) Avoiding use of lower frequencies to enable AC power to be carried by said electricity cabling to signalling or other devices for electricity utility network management;

(j) Transfer of data bi-directionally by infrared, Bluetooth or 802.11 wireless transmissions from handpieces or keyboards in end user premises to and from any multiplexing interface;

(k) Storage of data on a card, with or without integrated circuit chip in association with said remote control handpiece or wireless keyboard prior to transmission to or from said handpiece or keyboard. (1) Display of all or any said data on a television or computer monitor in end user premises; (m) Display of all or any of said data on a display panel integrated with said handpiece or cellular phone (n) Scanning means on or in association with said handpiece, cellular phone or wireless keyboard; (o) Activation of printing means in association with said interface by remote control handpiece, cellular phone or wireless keyboard.

25. A communications system as described in any previous claim where Orthogonal Frequency Division Multiplexing (OFDM) is utilised..

26. A communications system as described in any previous claim where digitally modulated data is downloaded for storage at the site of the communications system from remote sources for the purpose of providing data that can be selectively retrieved by end users connected to said communications system for printing out by a printer in end user premises.

27. A communications system as in claim 26 where digitally modulated data is retrieved by an end user connected to said system and stored as video signals and stored in a recorder in end user premises.

28. A communications system as in claim 26 where said digitally modulated data is retrieved by an end user and replayed through a television set or computer in end user premises.

29. A communications system as described in any preceding claim where data is relayed from end user premises using one coding system for security between end user and said cellular processing point, and another coding or encryption when said data is further relayed to a service provider to give a two stage dual security system for transmissions in whole or in part on electricity cabling.

30. A communications system as in any preceding claim where recording of transmissions from end users enables service providers to verify time of transmission signals from end users to individual communications system sites and correlate these into times of responses of end users connected to multiple communications system sites.

31. A communications system as in any previous claims where said communications system is linked to other such communications system sites by electricity cabling, or by satellite, or by wireless low power communications systems including spread spectrum transmissions for the purpose of transmitting between sites in manner that does not cause interference to other radio spectrum users, and links communities served by low voltage electricity grids that have said cellular processing points.

32. A communications system as in claim 31 where the sites referred to have global positioning system equipment for location purposes.

33. A communications system as in any previous claim where the communications system site and end users can, either in their own premises or remotely, control the operation of home appliances and other systems connected to electricity cabling.

34. A communications system as claimed in any preceding claim where the powerline used for communications transmission is the neutral conductor connected to power outlets within a building

35. A communications system as claimed in any preceding claim where the powerline used for communications transmission is the protective earth conductor connected to power outlets within a building.

36. A communications system as claimed in any preceding claim where polymer composites conducting or non conducting at radio frequencies are used for transmission or shielding purposes.

37. A communications system as claimed in any preceding claim which includes one or more cellular telephones of low transmission power and short range that transmit and receive data to and from electricity cabling connected to low voltage electricity grids.

38. A communications system as claimed in any claim preceding claim 33 which includes one or more cellular telephones of dual transmission power switchable to lower power when used to transmit and receive data to and from electricity cabling connected to low voltage electricity grids.

39. A communications system as claimed in any preceding claim where equipment for monitoring the medical condition of a patient is connected to the electricity cabling which is used for data transmission to or from such monitoring equipment.

40. A communications system as claimed in any preceding claim where video conferencing equipment is connected to electricity cabling for transmission of audio and video for conferences.

41. A communications system as described in claim 1 which is a point to multipoint transmission system.

42. A communications system as described in claim 1 which enables a portable data collection or transmission device to connect wirelessly with the electricity cabling in the walls of a building

43. A communications system as described in any preceding claim where the modems necessary to interface end user equipment to the powerline transmissions are built into said equipment.

44. A communications system as described in any preceding claim where quadrature amplitude modulation is utilised.

45. A communications system substantially as herein described and with reference to the accompanying drawings.