MXPA96004961A - Hybrid network of electricity and telecommunication distribution - Google Patents

Abstract

A telecommunications network for linking a plurality of premises or premises is described, typically comprising a fiber optic or coaxial cable (130), and a plurality of electrical power cables (134), each connected to a respective one of the premises to supply the electric power of the main conductors to these. Each of the power cables 134 is also connected to the fiber optic or coaxial cable (1130) so that the telecommunication signals are transmissible between the fiber optic or the coaxial cable and each of the power cables. A telecommunication signal is transmissible to the plurality of premises or premises by being transmitted along the optical fiber or the coaxial cable and subsequently along the respective power cable of each of the premises or premises.

Description

HYBRID NETWORK OF DISTRIBUTION OF ELECTRICITY AND TELECOMMUNICATIONS This invention relates to a method of injection, transmission, interconnection (termination), and signal detection, and to a power transmission network, i.e., a distribution network and / or transmission of electricity from main conductors, and a filter for it. In particular, it relates to the use of the networks and / or electricity lines of the main conductors, for the transmission of telecommunications (for example voice, data, images and / or video). In the United Kingdom, it is conventional to describe a power network of 33 kV and above as a "transmission network", and a network of less than 33 kV as a "distribution network". In this specification, the term "electricity distribution network and / or power transmission" was commonly used, although general references to energy networks and signal transmission can be interpreted as they apply to all those networks. Traditionally, telecommunications signals have been transmitted over independent networks, for example telephone lines. More recently, in order to simplify and increase the efficiency of telecommunications services to premises or REF: 23383, domestic or industrial premises, research has been done on the use of existing electricity transmission and distribution networks to transmit or conduct telecommunications services . In the Applicant International Patent Application of the Applicant, PCT / GB93 / 02163, a transmission network and a filter for the same are described. This describes the use of telecommunication signals that have a carrier frequency greater than about 1MHz over a power transmission network. The teachings and description of that patent application should be taken as reference in relation to the present invention, and incorporated herein by reference. In such carrier frequencies, it has been found that the cables of a power transmission and / or distribution network exhibit pseudo-coaxial characteristics and therefore the attenuation of a signal transmitted along the cables is reduced. In this way, both voice frequency and data signals can be transmitted at carrier frequencies greater than about 1MHz, allowing a larger available spectrum and higher transmission capacity. However, it has been found that the attenuation still affects the limit of the distance over which the signals of a given carrier frequency and bandwidth can be effectively transmitted. In, for example, a network of 415 volts the carrier frequency may preferably be between 1-10 MHz, and in, for example, a network of llkV perhaps between, for example, 1-20 MHz or possibly 5-60 MHz. The signals of this frequency can be transmitted over long distances (using relay stations if necessary) and therefore a network used in this way is suitable for general telecommunication and telephony signals. However, broadband telecommunications signals, such as television communications, generally require a higher frequency (or frequencies) and bandwidth. As indicated above, such signals are therefore usually transmitted over a separate broadband telecommunications network, for example coaxial cable, optical fiber, etc. A carrier frequency of up to hundreds of MHZ can be used over a network as described in PCT / GB93 / 02163, although the distance over which a signal with a particularly high carrier frequency can be transmitted is limited by the sensitivities of the dynamic range and the energy levels deployed over the network - possibly around 7-40 meters over a typical network in the United Kingdom.

The main purpose of the present invention is to provide a transmission network that alleviates some or all of the above problems. In consecuense, in a first aspect, the present invention provides a network for linking a plurality of premises or premises comprising a broadband telecommunications network section and a plurality of electric power cables, each connected to a respective one of the premises for supplying the electrical power from the main conductors to these, each of the power cables is also connected to the section of the broadband telecommunications network so that the telecommunication signals are transmissible between the telecommunication network section of broadband and each of the power cables, wherein a telecommunications signal is transmissible to and / or from the plurality of premises to be transmitted along the broadband telecommunications network section and also along the each respective power cable. In this way, the independent telecommunication network (preferably external) can be used to propagate telecommunication signals over a long distance, with the power transmission / distribution network (preferably external) being used to propagate the telecommunications signal from the network of telecommunications towards for example the premises of a user and vice versa, that is to say that the communications can be bidii-eccionales. By "external", it should be understood that the signal transmission network, ie the power network and / or the telecommunications network is external to any construction or location such as an office or home. Within such constructions, the transmission distances are typically short and therefore the losses of attenuation are relatively unimportant. The broadband telecommunications network can be a standard broadband distribution network, for example a coaxial, pressed pair or fiber cable. Such telecommunications networks are currently available in most countries. However, typically, the high costs and inconveniences associated with such telecommunications networks are not the initial installation of the main network but the connection of the main network to the users' premises. The present invention allows existing power distribution networks (which are commonly fed into most suitable premises) to be used to connect the existing telecommunications network to the desired premises. This avoids costs e * >; additional inconveniences of installing an additional standard telecommunications network. Typically, the distance between the infrastructure of the existing telecommunications network and the premises to which you wish to connect is short. Therefore broadband telecommunications signals can be transmitted over the power transmission / distribution network without loss of attenuation having any significant effect. Preferably, the present invention further includes satellite receiving means for receiving telecommunications signals from a satellite transmitter, wherein the telecommunications signal is transmittable from the satellite transmitter to the plurality of premises via the satellite receiving means, the of the broadband telecommunications network and power cables. Alternatively or additionally, the satellite receiving means can be replaced or supplemented by other means of receiving telecommunications signals, such as a TV antenna, telephone connection, data connection, etc. Preferably, the network includes a plurality of interconnection units, each of the interconnection units connects one of the power cables to the section of the broadband telecommunications network, each of the interconnection units includes filter means of high pass to allow high frequency telecommunications signals to pass between the broadband telecommunications network section and the dz energy cable, and to prevent electrical power signals in the low frequency media from passing between them. In a further aspect, the present invention provides a method of transmitting a telecommunications signal between a pair of constructions, including the steps of transmitting the signal from a first construction along an external power cable to provide the energy of the main conductors to the first construction, followed by the transmission of the signal along a section of the broadband telecommunications network, followed by the transmission of the signal along a second external power cable to provide the power electrical from the main conductors to the second construction. Preferably the telecommunication signal has a carrier frequency greater than about IMHZ. The carrier frequency can, in fact, be less than IMHZ ie 800kHz or even low as 600kHz, but as it decreases so does the bandwidth. The term "carrier frequency" refers to the frequency or unmodulated frequencies of the carrier signals, and not to the frequency of the telecommunication signal or signals once modulated. A plurality of telecommunications signals may be provided, each of which has different carrier frequencies. The power network may include one or more phases, and may be a polyphase network including, for example, one or more than 2, 3, 4, 6, 7, etc. phases. Different sections of the network can include different numbers of phases. Preferably the power network is a single-phase network, for example, consisting of one or more single-phase cables that connect one or more user premises or constructions to a main polyphase (e.g., 3-phase) portion of the electricity distribution network. The broadband telecommunications signals are taken for example via an amplifurcation, from the main broadband distribution network (for example the coaxial or fiber cable) via the appropriate interconnect unit and fed into the single phase cable of the cable. fertilizer via a suitable conditioning unit. The signal can be amplified if necessary.

Preferably the power network is unbalanced, that is, it provides unbalanced transmission characteristics. The power network cables can be shielded or coated, for example with a suitable metal material, which allows the cable to behave like a pseudoaxial element to provide an unbalanced transmission network at the transmission frequency of the present invention. Preferably the power network is a major power network (for example aerial and / or underground) including, for example, any or all sections of 132kV, 33kV, llkV, 415v and 240v. The voice and data signals may be transmitted over any or all sections of the power network by detection, "_5 amplification and / or regeneration and appropriate reintroduction as and when necessary." In a preferred embodiment, fully dual installations are provided. , ie, that the signals can be transmitted and / or received in all the directions simultaneously A network according to the present invention can be used for many purposes of voice frequency transmission and / or data, such as remote reading of electricity meters, bank operations and purchases to _5 distance, energy management systems, telephony (voice), switched telephony, security systems and / or interactive data services, multiple media services and television. The present invention also provides a communications apparatus (hereinafter referred to as a "network conditioning unit") for use with a network according to the above aspects of the present invention. The network conditioning unit includes a portion of low pass filter or portions for filter the main energy signals of high amplitude and low frequency, that is, separate them from the communication signals and allow them to pass through the conditioning unit. The unit also includes a high-pass coupling element to insert and remove telecommunications signals from the network and, preferably, - - an impedance termination element similar to the characteristic impedance of the network at that point. The use of such a unit ensures that high frequency telecommunications signals do not contaminate the internal low-voltage wiring present within a room, and / or that the noise sources of the wiring of the internal low-voltage rooms do not contaminate or corrupt the high-frequency telecommunications signals that are transmitted over the transmission network and / or external electricity distribution.

Preferably, the effects of the variable electric charge (ie the load impedances) of all items that are coupled or connected to the network, from time to time, and that use electrical power (ie electric charges) are isolated of the communication signals by the action of the elements of the low pass filter of the conditioning units. Preferably an electric filter is used in the interconnection between the external distribution network and the internal network of the premises, for example, a house of a user to ensure that the two signals are separated. Such filters will have a minimal effect on the normal domestic electricity supply. The filtering element of the present invention, which has the purpose of reducing the telecommunication signals entering the internal network of the users' premises, preferably having a drop of not more than 1 volt therethrough provides at the same time a charge of lOOamp from a single-base source of 240v, 50HZ. Preferably the network conditioning unit provides an impedance matching between the reception / transmission devices in the power network. Additionally, the network conditioning unit may transmit a raw load or fault current to the energy frequencies while it is transmitting the voice and data signals. In an additional aspect, the present invention provides a method of transmitting signals using a network as described herein. Where the signals are transmitted along a polyphase electricity power cable (for example of three phases), the propagation of the signal can be between any or all of the phases and the connection to ground. In a preferred embodiment the signal is injected between only one of the phases and the ground connection, which also provides the unbalanced transmission characteristics and the cable behaves like a pseudo-coaxial transmission line. Where the signals are transmitted along a single-phase electricity distribution service cable, a pseudo-coaxial effect can also be obtained. Single phase cables can typically be either concentric or concentric divided. In the case of a divided concentric cable, means (such as a coupling or capacity between the parts of the divided concentric liner) may be provided so that at the desired frequency the cable behaves like a standard concentric cable. In this way a pseudo-coaxial effect is achieved and the cable provides an unbalanced transmission characteristic. A wide range of different transmission techniques are available for use with communication by the electric power line, each of which uses several modulation methods including amplitude, frequency to a phase; simple, double and residual sideband, pulse position, width and amplitude; Frequency shift manipulation (FSK), Gaussian filtered FSK (GFSK), Gaussian minimum shift manipulation (GMSK), Quaternary phase shift manipulation (QPSK), Orthogonal quaternary phase shift manipulation (OQPSK), Amplitude modulation Quadrature (QAM); Pi / 4 QPSK etc, along with several techniques of ultiplexión, demultiplexión and multiple access including the division of frequency (FDM) (FDD), of time (TDM) (TDD), of code (CDM) (CDMA) etc. It has been determined that the spread spectrum method offers inherent security and good interference rejection characteristics. These properties are achieved using the large bandwidth and consequently require the design of a specific filter. A large number of standard wireless telephone communication techniques may be suitable for transmitting the signal over a conditioned network. The appropriate standards can be CTO, CTl and CT2, AMPS, DECT (Wireless Telephony Standard European Digital), IS-54, IS-95, GSM, Q-CDMA, R-CDMA, UD-PCS, PHS, PACS, TACS, ENTACS, NMT450, NMT500, C-450, RTMS, Radico 2000, NTJ, JTACS and NTACS, DCS 1800 etc. The conditioning network of the unit preferably includes a low pass filter comprising a main inductor arranged between an electricity input of the main conductors and the electricity output of the main conductors and connected at each end thereof to a signal input / output line, which is arranged in parallel to the electricity input of the main conductors and the electricity output of the main conductors, the two connections include a first capacitor and a second capacitor, each of a capacitance default depending on the portion of the frequency spectrum that is to be used for communication purposes. In this arrangement, the main inductor operates to prevent communication signals from the signal input / output line from entering domestic / industrial premises. This inductor is therefore preferably of a high inductance such as 100μH to 200μH for frequencies of 1MHz and higher.

The first capacitor, which connects the electricity input of the main conductors and the signal input / output line acts as a coupling capacitor to allow signal communication through the signal input / output line attenuating the time all the low frequency components at or around the main electricity supply frequency (ie 50 / 60Hz). The second capacitor arranged between the electricity output of the main conductors and the signal input / output line provides additional attenuation of the communication signals and is connected via the signal input / output line to ground. In the case of a failure of either the first or second capacitor such a capacitor is preferably provided with fuse arranged between the first - > second capacitor and the signal input / output line. In addition, an additional safety precaution can be incorporated by providing a second fixed inductor between the connections between the signal input / output line and the first and second capacitors. This inductor has no effect on communication frequency signals but will provide a ground path if the first capacitor develops a fault, thereby allowing the first fuse to melt without allowing the power frequency signal over the input line / signal output. The inductance of the main inductor depends on the material from which it is made and the cross section of the wire coil around the core. The inductance of lOμH previously specified is preferably a minimum and with the use of a better core material a greater inductance can be obtained, for example in the order of 200μH. Alternatively, a number of inductors connected in series could be used. The coupling capacitor has a capacitance preferably in the range of 0.01 to 0.50μF and the second capacitor that connects the electricity output of the main conductors with the input / output line of the signals and the ground connection has a capacitance preferably in the interval from 0.001 to 0. 50μF. The second inductor arranged on the signal input / output line preferably has a minimum inductance of approximately 250μH. This inductor therefore has no effect on the communication frequency signals on the signal input / output line. The conductor used to construct the 250μH inductor should be of sufficient cross-sectional area to take the fault current since the decoupling capacitor could fail to condition a short circuit. Preferably, any spurious self-resonance in the inductive or capacitive elements should be avoided. When the internal cutting frequency of the conditioning unit increases, the minimum values of the inductance and capacitance can be reduced proportionally. In a preferred embodiment the filter is mounted in a given box to provide a good ground connection and to avoid radiation of the communication signals. In a further aspect, the present invention provides a signal transmission network that includes at least a portion of a telecommunications network and at least a portion of a power transmission and / or distribution network. In a further aspect, the present invention provides a power transmission and / or distribution network that includes input means for the input of a telecommunications signal to the power transmission network, (for example a transmission network and / or distribution of electricity) from a telecommunications network, and means of output to remove a similar telecommunications signal from the power grid.

In a further aspect, the present invention provides an electricity distribution network and / or energy transmission having a number of phases, the number of phases is chosen from the list 1, 2, 4, 5, 6, 7, 8 , 5 9, .... n (where n is an integer greater than 9), but preferably having 1 or 2 phases, and including input means for the input of a telecommunication signal having a carrier frequency greater than approximately 1MHz over at least one of the phase conductors of the network and output means to remove the telecommunications signal from at least one of the other phase conductors of the network. In a further aspect, the present invention provides an electricity distribution network and / or transmission of unbalanced energy at least in part, the - which comprises a coated cable, the network includes input means for the input on the network of a telecommunications signal having a carrier frequency greater than about 1MHz and means of output to remove the network telecommunications signal, the signal is transmissible along the part of the network that has the cable coated. In a further aspect, the present invention provides a main line and a distribution network of electricity and / or power transmission with branches in multiple points that includes input means • < . for the input over the network of a telecommunication signal having a carrier frequency greater than about 1 MHz and means of output to remove the telecommunication signal from the network. In a further aspect the present invention provides a distribution network of electricity and / or power transmission at least part of which is external to a construction, the network includes input means for the input on the network of a telecommunications signal that has a carrier frequency greater than about 1MHz and means of output to remove the telecommunications signal from the network, the signal is transmissible along the external part of the network. In a further aspect, the present invention provides a signal transmission method that includes the input of a telecommunications signal having a carrier frequency of more than about 1 MHz from at least one phase conductor of a distribution and / or transmission network. of electrical power, and the subsequent reception of the signal is from at least one other phase conductor of the network, the network has a number of phases, the number is chosen from the list 1, 2, 4, 5, 6, 7, 8, 9, n (where n is an integer greater than 9), but preferably has 1 or 2 phases.

Any or all of the above aspects may include the features described elsewhere in this specification. The embodiments of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a schematic diagram of a part of a network according to the aspects of the present invention; Figure 2 is a schematic diagram of a first transmission system for a network shown in Figure 1; Figure 3 is a schematic diagram of a second transmission system for a network shown in Figure 1; Figure 4 is a schematic diagram of a third transmission system for a network shown in Figure 1; Figure 5A is a cross section through a typical three-phase cable; Figure 5B is a cut through a typical coaxial cable; Figure 6 is a preferred embodiment of a network conditioning unit used in the present invention; Figure 7 is a second embodiment of a network conditioning unit used in the present invention; Figure 8 is a plan view of a network conditioning unit; Figure 9 is a view of a circuit board for the network conditioning unit of Figure 8. Figure 10 is a schematic diagram of a network conditioning unit as used in the present invention. FIGS. 11 and 11b are a second and third schematic diagrams of a network conditioning unit as used in the present invention.; Figures 12A, 12B and 12C show views in section through a concentric, divided and pseudo-concentric concentric cable, respectively; and Figure 13 shows a hybrid network according to an aspect of the present invention. Figure 1 shows in general a network 40.

The electricity of the main conductors enters the network from a transmission line of llkV 42, via transformer 44 and a three-phase network of 415v 46. The three-phase network of 415v is supplied to a number of places, such as buildings or constructions 48. Each of these buildings or constructions can receive only a single-phase electricity supply or alternatively can receive a three-phase power supply. The voice and data signals can be injected into the network (or alternatively received from the network) to / from a telecommunications network (eg coaxial cable, fiber or twisted pair), or an additional part of the distribution network / transmission of electricity, at an induction point 50, to be transmitted and / or received by the users in the premises 48. These signals can be narrow bandwidth, for example, telephony signals, or broadband, for example , television signals, as desired, depending on the attenuation and distance to be traveled along the power distribution network. To separate the voice and data communication signals from the high amplitude and low frequency energy signal each source and / or destination of the signal is provided with a network conditioning unit 52 - shown in greater detail in FIG. . This network conditioning unit includes a low pass filter to separate the two signals. A (high current) conditioning signal 51, also shown in Figure 11b - can be installed between the electricity transformer and distribution 44 and the injection point 50 to further remove the noise from the transformer of the conditioned network. The unit 51 is equipped with a high current inductor. Figure 13 illustrates a portion of a hybrid signal transmission network according to the present invention. A portion of a cable 130 of a broadband telecommunications network (eg, a coaxial cable, fiber or twisted pair) is illustrated running (for the propocuments of this example) parallel to for example a three-phase electricity distribution cable 132. The electricity distribution network 132 may also transmit or transport telecommunication signals of the appropriate carrier frequency and bandwidth, as described elsewhere in this specification and in that of PCT / GB93 / 02163. The telecommunications network 130 broadcasts broadband telecommunications signals, for example, television signals. The telecommunication signals, for example the television signals, which can be in the analogue and / or digital format, are introduced (or removed) from the telecommunications network 130 on (or from) a portion 134 of the network. external electricity distribution 132 via a conditioning unit 136. The conditioning unit 136 allows telecommunication signals to be input on (or removed) the power cable 134 without any of the telecommunication signals entering the power distribution network. electricity 132 or electricity signals enter telecommunication network 130. Similarly telecommunications signals may be introduced into the telecommunications network from portion 134 of electricity distribution network 132. If necessary, a coaxial / fiber 138 interconnect unit and an amplifier (e.g. a broadband amplifier) 140 for the interconnection between the telecommunications network 130 and the conditioning unit 136. The amplifier 140 may be bidirectional (as shown) or unidirectional (in any direction, as required). Preferably the portion 134 of the external electricity distribution network 132 is a single-phase cable. This may be a single-phase concentric cable or a separate concentric two-phase cable installed to act as a pseudo-concentric cable as described with reference to FIGS. 12A, 12B and 12C. Typically, this single-phase cable connects user premises 142 to, for example, the three-phase electricity distribution network 132. Located on or near the users' premises 142 can be found a second conditioning unit 144, which separates telecommunications signals 146 from electricity supply 148. This distribution of both electrical power and broadband telecommunications signals is facilitated without harming each other and without the need for additional fiber / coaxial links between telecommunication network 130 and telecommunications networks. user premises 142. A plurality of such links of the telecommunications network 130 may be made to the corresponding plurality of user premises. Also, the telecommunications network 130 can be connected directly to the broadband telecommunications signal transmitter, or alternatively it can be connected via a radio or satellite link 150. The conditioning units 136 can be located for example at street level, such as a pillar or basement and adjacent to the electricity service position within the premises of the users. The conditioning units 142 can be located, for example, close to the users 'premises or within the users' premises such as inside a HRC cutting unit and / or the electricity meter. Figure 2 shows a portion of the three-phase network 40 in which and from which the data signals can be transmitted and received using the conditioning units of the network 52. The network cable is coated, ie surrounded by a liner 41, for example along all or substantially all its length. As an example, the data signals could be transmitted over the yellow phase of the network by the conditioning unit of the network 52A, ie, that the signal is applied between the yellow phase and the earth as shown. The transmitted data can then be received by any or all of the conditioning units 52B, 52C and 52D which are connected to the yellow, red and blue phases respectively. In other words, the transmitted data can be given over any phase of the cable, including the phases over which the signals were not injected by the transmission unit. This is due to the mutual capacitance between the phase conductors that produce an effective pseudo-coaxial nature of the three-phase cable. As can be seen, the data can be transmitted and received by each unit.

Each phase of network 40 is shown including a transformer 43. Typically this is effected by a single three-phase transformer for all three phases, and not by three separate single-phase transformers, although the latter may be possible. Figure 3 shows a portion of a three-phase power network 40 in which and from which the data signals can be transmitted and received using four network conditioning units 52. As shown, the data signals are transmitted through of two phases of the three-phase network - in this case the red and blue phases. If one or more phases (for example the yellow phase in Figure 3), the unused phases can be determined to provide an appropriate impedance. This can be done using an "L" circuit, that is, an inductor in series with a capacitor derived on the side of the transformer. This provides an optimum impedance and ensures that an RF signal, which is coupled between, for example, the red and yellow phases, is not derived downward by a low impedance transformer connection. This is particularly useful if there is sufficient inductive reactivity in, for example, the transformer connection point of the yellow phase. In Figure 4 there is shown an alternative transformation system to that of Figure 2, in which the data signals are transmitted through the three phases, ie blue, red and yellow, of the three-phase network 40. Figure 5A shows a simplified cross-section of a three-phase power cable 54, including a red phase 56, the yellow phase 58, and the blue phase 60. The data signals are transmitted between the blue phase 60 and the earth 62, and are injected to the network via the conditioning unit of the network 52. At high frequencies, the mutual capacitance between the phases effectively produces a short circuit. Therefore, such a transmission system gives a pseudoaxial characteristic, approximately equivalent to the coaxial cable shown in Figure 5B. The mutual capacitance between any of the two phases in the three-phase cable is shown schematically as 64 in Figure 5A - there is a similar mutual capacitance among the other parts of the phase. The basic elements of a network conditioning unit 101 according to one aspect of the present invention are illustrated in FIGS. 11 and 11b. Figures Ia and llb show the conditioning units designated 52 and 51 in Figure 1, respectively. The conditioning unit can be considered equivalent to the low pass filter 100 and a coupling capacitor element 102 (which can be considered to be the high pass filter element). The low-pass filtering element 100 allows the energy of the main conductors to be managed from the distribution network to a consumer while avoiding high-frequency communication signals from entering the premises of the consumers. A coupling capacitor, high pass filtering element 102, is provided for coupling the high frequency communication signals to the distribution network while avoiding the energy of the main conductors entering the communication apparatus. The components of the conditioning unit may be installed in, for example, suture housing of the electricity meter located in the users' premises, or it may possibly be installed in a compartment on the back of such meter. Alternatively, the necessary components can be located in, for example, a high interruption capacity (HRC) fuse or cutting unit. Referring now to Figure 6, a mode of a conditioning unit (essentially a filter) according to one aspect of the invention is indicated, generally by reference numeral 10, and is connected between the electricity input of the main conductors 12. and an output of electricity from the main conductors 14. A signal input / output line 16 is also connected to the filter. The power line of the main conductors is a standard 50Hz main electrical power supply, which provides a domestic electrical power source of 240v at a maximum current of 100 amps for normal use. The filter 10 is mounted in a metal box, which prevents the radiation of the communication signals to externally located devices and a ground connection 18 is provided for the signal input / output line 16. The filter 10 includes a first or main inductor 20 formed of rolled wire of a ferrite rod of 10mm diameter, 200mm in length with 30 turns of wire around it. This provides an inductance of approximately 50μH. This may be a minimum for the characteristics of the signals used. The use of better materials or a plurality of inductors in series could increase the inductance of the inductor to, for example, approximately 200μH. Each end of the main inductor 20 is provided with a connection to the signal input / output line 16. A first connection 22 between the electricity input of the main conductors 12 and the signal input / output line 16 comprises a first or coupling capacitor 24 having a capacitance between 0.01 and 0.50μF, and preferably around O.lμF. This coupling capacitor 24 is connected to a first fuse 26, which is arranged to melt in the event of a fault or a fault in the capacitor 24. A second connection 28 includes a second capacitor 30 having a capacitance of between 0.001 and 0. 50μF, preferably around O.lμF. This capacitor provides additional attenuation of the communication signals by shortening the ground or ground connection 18. A second fuse 32 is provided to melt if a fault develops in the second capacitor 30 thereby preventing further damage to the unit . The signal input / output line 16 is connected to include a second inductor 34 having a minimum inductance of approximately 250μH. This inductor is provided as a damage limiter in the case of failure of the coupling capacitor 24. In the case of such failure this inductor provides a path to the ground connection 18 for the electric power frequency of the main 50Hz conductors thereby fusing the fuse 26. The inductor has no effect on the communication frequency signals present on the signal input / output line 16. Figure 7 shows a second embodiment of a filter according to one aspect of the present invention. The filter 70 includes a pair of inductors Ll and L2 arranged in series between an electricity input of the main conductors 72 and an electricity output of the main conductors 74. A preferred value of the Ll and L2 is approximately 16μH. Connected between the RF input line 80 and the input of the main conductors 72 is a first fuse Fl and the capacitor Cl, and connected between the RF input 80 and the ground connection is a third inductor L3, which It acts as an RF shock coil and has a typical value of 250μH. Connected in a similar way between the connection point of Ll and L2 and the ground connection are a second fuse F2 and a second capacitor C2. Connected between the electricity input of the main conductors 74 and the ground connection are a third fuse F3 and a third capacitor C3. The typical value for capacitors is around O.lμF and for fuses of approximately 5 amps HRC (high interrupting capacity). The values given for those components are exemplary only, and the different preferred values will be appropriate for other design frequencies. Returning now to Figure 8, a typical accommodation arrangement for a network conditioning unit according to one embodiment of the present invention is shown. The main inductors Ll and L2 are housed within a shielded box 90. They show several connections, including a communication interconnect gate 92 to which the user's communication equipment could normally be connected. However, as shown in Figure 8, this gate may terminate in an impedance balance gate terminator 94. Figure 9 shows a circuit board 96, which is installed inside the unit 90 of the figure 8 and is housed in the back of the circuits for the barrier conditioning unit of figure 7. Connections A, B, C, D and E are shown which are connected to the appropriate points of the box shown in FIG. Figure 8. Figure 10 is a schematic representation of a conditioning unit of the network 52, showing the various building blocks 80-86 of the network conditioning element. In order to design a suitable network conditioning unit, the circuits represented by blocks 81 and 86 must be high impedance elements over the frequency spectrum of: • > communications required (for example 1 MHz and above) and elements of low impedance at the frequency of the electricity supply of the main conductors (ie 50 / 60HZ), that is, that these elements are inductors. Similarly, blocks 80 and 82 must be either low impedance coupling elements over the required communication frequency spectrum and high impedance insulating elements at the frequency of the electricity supply of the main conductors, ie they are capacitors. 5 Provide fuse safety links - • Fault current limitation HRC (high interruption capacity) (84 and 85) in series with elements 80 and 82. An additional impedance balance network 83 can be included to be connected to the 0 communications gate. This element may be external to the conditioning unit of the network 52. The optimal values of the elements 81, 80, 82 and 86 will depend on the factors that include: a) The required frequency range over which the network is going to be conditioned. b) The length of the unit of the network that is to be conditioned. c) The number and type of charges that can be found in the network. d) The characteristic impedance of the phase conductors of the network with respect to the earth, that is to say, external electrical sheath conductor. e) The impedance of the communication interconnection devices. The network conditioning unit can be filled with air, inert gas, resin or petroleum compounds depending on the location and nominal load and / or fault current regimes of the conditioning unit. It can also be searched indoors, mounted on poles, buried underground or inserted into columns of street lamps. Similarly the elements 81 and 86 may comprise a number of individual inducers in series, and if interconnection is not required, for example, a street lamp, the elements 84, 80, 83 and 86 may be omitted. The elements 80 and 82 may comprise a number of capacitors in series, configuration in series and / or in parallel depending on the working voltages found, ie 240, 415, llkV,, 33kV, etc. Alternatively or additionally, the elements 80 and 82 may comprise two or more capacitors in parallel to overcome, for example, deficiencies in the design of the capacitor when a network is conditioned over a relatively wide frequency range, for example 50 MHz at 500MHz. In addition, elements 81, 35, and 82 of the network conditioning unit can be cascaded, if required. In a typical design, the greater the number of cascading elements, the more outstanding will be the response of the progressive attenuation of the filter and the greater its attenuation. Figures 12A, 12B and 12C show sectional views through concentric, concentric and spaced concentric and pseudo single-phase cables, respectively. A typical single-phase concentric cable (as illustrated in Figure 12A) consists of a central metallic conductor core (typically aluminum) 110 surrounded by an insulating layer 112 (typically PVC). Around the insulating layer 112 are a plurality of metal conductors 114 (typically copper) on which there is an insulating and protective liner 116 (typically PVC). In use the neutral and the earth are combined in the outer shell of the metallic conductors 114.

A separate concentric cable (as illustrated in Figure 12B) is similar to the concentric cable except that the outer layer of the metal conductors 114 is separated into two portions - for example an upper portion 115 and a lower portion 117. Those portions are divided. by the insulators 118, 120 and in use the neutral and the earth are separated so that the portion of the outer metallic shell contains only one of them. In order to maintain the pseudocoaxial effect in the concentric service wires separated at the desired transmission frequencies (for example above 1MHz) one or more capacitors 122 can be connected between the upper and lower portions 115, 117 of the outer metallic sheath 114. These capacitors can installed, for example, at the termination and / or cable conditioning points. It should be noted from the foregoing that a single filter is provided, which effectively separates the signals having a frequency spectrum indicative of radio communication signals from those of the power supply of the standard main conductors without significant loss of energy or quality in any signal. In this way electricity distribution and / or transmission networks can be used both to provide electricity supply and for the propagation of broadband telecommunications signals, which can be in the analog and / or digital format. The use of such a filter at each of the consumer supply points in a low voltage underground electricity distribution network provides a suitable conditioned network for the transmission of high frequency communication signals together with the distribution of 50MHz, 240V , simple and 415v, provides three-phase electricity. Providing such a conditioned network constitutes a further aspect of the invention. The invention is not limited to the foregoing details and variations may be made to it within the scope of the invention.

It is noted that in relation to this date, the best method known by the applicant to carry out the practice is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (13)

1. A network that links a plurality of premises or premises, characterized in that it comprises: a broadband telecommunications network section, and a plurality of electrical power cables connected to ground to a respective one of the premises to supply the electrical energy of the conductors Main to these, each of the power cables is also connected to the section of the broadband telecommunications network so that the telecommunication signals are transmissible between the section of the broadband telecommunications network and each of the power cables, wherein a telecommunication signal is transmissible and / or from the plurality of premises to be transmitted along the broadband telecommunications network section and also along the respective power cable of each of premises or premises.

2. A network according to claim 1, characterized in that it includes satellite reception means for receiving the communication signals from a satellite transmitter, wherein the telecommunications signal is transmissible from the satellite transmitter to a plurality of premises via the means of satellite reception, the section of the broadband telecommunications network and the power cables.

3. The network according to claim 1 or claim 2, characterized in that it includes a plurality of interconnection units, each of the interconnection units connects one of the power cables to the section of the broadband telecommunications network, each one of the interconnection units includes high-pass filter means, to allow high-frequency telecommunications signals to pass between the broadband telecommunications network section and the power cable, and to prevent electrical power signals of the low frequency main drivers pass between them.

4. The network according to any of the preceding claims, characterized in that the electric power cables are totally external to the plurality of premises or premises.

5. The network according to any of the preceding claims, characterized in that the section of the broadband telecommunications network includes any or all of optical fiber, twisted pair or coaxial cable.

6. A method of transmitting telecommunication signals between a pair of constructions, characterized in that it includes the steps of: (i) transmitting the signal from a first building along an external power cable to supply the power of the main conductors to the first building, followed by (ii) transmitting the signal along a section of the broadband telecommunications network, followed by (iii) transmitting the signal along a second external power cable to supply the electrical power of the main conductors to the second building.

7. The method of transmitting telecommunication signals according to claim 6, characterized in that the carrier frequency of the telecommunication signals is at least 1MHz »

8. A network, characterized in that it is substantially as described herein, with reference to Figure 13 of the accompanying drawings.

9. An electricity transmission and / or power transmission network, characterized in that it has a number of phases, the number of phases is chosen from the list of 1, 2, 4, 5, 6, 7, 8, 9, ... n (wherein n is an integer greater than 9) and includes input means for the input of a telecommunication signal having a carrier frequency greater than about 1MHz over at least one of the phase conductors of the network and means of output to remove the telecommunications signal from at least one other phase conductor of the network.

10. An electricity transmission network and / or unbalanced power transmission, characterized in that at least a part of this comprises a coated cable, the network includes input means for the input to the network of a telecommunications signal having a higher carrier frequency approximately 1MHz and means of output to remove the telecommunication signal from the network, the signal is transmissible along the network that has the cable covered.

11. An electricity distribution network and / or power transmission of a main line and branches at multiple points, characterized in that it includes input means for the input to the network of a telecommunications signal having a carrier frequency greater than about 1 MHz and means of output to remove the telecommunications signal from the network.

12. An electricity distribution and / or power transmission network, characterized in that at least part of it is external to a construction, the network has input means for the input to the network of a telecommunications signal having a carrier frequency greater than Approximately 1MHz and means of output to remove the telecommunications signal from the network, the signal is transmissible along the external part of the network.

13. A signal transmission method, characterized in that it includes the input of a telecommunications signal having a carrier frequency greater than about l Hz over at least one phase conductor of an electrical power transmission and / or isolation network, and the subsequent one reception of the signal from at least one other phase conductor of the network, the network has a number of phases, the number of phases is chosen from the list of 1, 2, 4, 5, 6, 7, 8, 9,. ..n (where n is an integer greater than 9).