MXPA00007072A - Universal signal distribution system - Google Patents

Abstract

The present industrial invention concerns a system for the distribution in a condominium and/or community environment of a plurality of television signals, and/or audio signals, and/or digital audio and/or video signals transmitted with different standards. According to the invention, one or more digital signals can be received by a single user of the system by means of a frequency conversion into a predetermined channel, which can be accessed by said user only. The digital signal being present in said channel always has the same modulation and can be selected by said user through control means which send a control signal to selection means.

Description

UNIVERSAL SYSTEM FOR SIGNAL DISTRIBUTION FIELD OF THE INVENTION The present invention relates to a system for distributing a plurality of television signals, and / or audio signals, in particular those belonging to different standards, in a condominium and / or community environment By condominium is meant an apartment block, and by community a block of one or more buildings. BACKGROUND OF THE INVENTION The development of digital technology, in particular signal compression techniques, leads to the introduction of digital television by means of. terrestrial, cable or satellite transmission. Digital television offers the advantage of a wider availability of programs (for example, a number of 4 to 6 digital programs can, in fact, be distributed in the frequency band occupied by an analog channel), and the implementation of the new known services as interactive, such as video on demand, called VOD (Video On Demand) or near-order video NVOD (Near Video On Demand). Obviously, in order to receive such new digital signals, equipment different to those used for the reception of analog signals is required, which can lead to differences of interest, for example, among residents in a condominium or community. In fact, many users wish to have access to the new programs and services available, while other users - either because they are not interested in news or for economic reasons - resort to the rules for the management of condominiums, which impose the approval of the majority for the fact of implementing such novelties, also considering that there is a high degree of indetermination around their real cost / benefit ratio. The additional inconveniences are presented by the fact that such interactive services also require, for the distribution system, not only be able to receive signals from a distributor, the so-called downstream signals, but also be able to transmit signals to the distributor, the so-called upstream signals. On the other hand, in most cases, both interactive programs and services are provided by payment, through a conditioned access system managed by the broadcaster and based on the use of smart cards, where each user must be able to operate the distribution system through smart cards, in order to decode the programs acquired under exclusivity. Now, the already known complexity of the installation of the systems will obviously increase to a considerable extent by virtue of all these additional functions required for the distribution system. From US-A-5 579 964 a system is known for the distribution of multiple received signals having different formats using a single previously existing network. The system described therein is provided for a preliminary conversion of all received signals into a bus or channel signal having a certain bandwidth (1GHz). This bus signal runs on a bus or channel that constitutes the distribution network. Each received signal is converted into a predetermined frequency position placed in the range of said bandwidth. A control computer in interface with the bus also adds addresses and commands in a predetermined frequency position to the bus signals, according to the needs of the user. From EP-A-0 457 673, a control system is known for apparatuses that reproduce audio / video in a community. Said system is conceptualized in such a way that the audio and video information arrives from each electronic device is of muti-plexion frequency in a specific channel in a common bus signal. In addition, a channel containing information is provided, which indicates the audio / video information distributed to the respective channels and information indicating the room (the input) used by the electronic device in its respective channel. The reason for giving such information is to allow the other user to know the channels and devices that are in use, to avoid the selection of the used channels and the alteration of the system. DESCRIPTION OF THE INVENTION The present invention has the purpose of providing a distribution system in which, resolving the above disadvantages, the distribution of a plurality of services in a condominium and / or community environment is allowed, regardless of the type of standards of the received signals and the time at which such signals become available. A further purpose of the present invention is to provide a system of digital signals in a condominium and / or community environment, which allows a gradual implementation of the system based on the free decision of each user separately, obviously without affecting the service and supplied by the system. A further purpose of the present invention is to provide a system for distributing digital signals in a condominium and / or community environment, which allows each user to use the digital signals in a bidirectional manner, without affecting the service already provided by the user. system . A further purpose of the present invention is to provide a quick installation of the system associated with the use of a smart card, while protecting the interests of the broadcaster as well as the privacy of the user. To achieve such purposes, the object of the present invention is a distribution system in a condominium and / or community environment that offers the features of the appended claims, which form an integral part of the present invention. The additional objects and advantages of the present invention will be obvious from the following detailed description and from the appended drawings, which are only provided by way of non-limiting example, wherein: - Figure 1 shows a subdivision of the band of frequency used for signal distribution; Figure 2 shows a known system that distributes a plurality of signals in a condominium and / or community environment; Figure 3 shows a system for distributing a plurality of signals in a condominium, and / or community environment according to the invention; Figure 4 shows a first variant mode of the system that distributes the plurality of signals in a condominium and / or community environment according to Figure 3; - figure 5 shows a detail of the first variant mode represented in figure 4; Figure 6 shows a second variant mode of the system that distributes a plurality of signals in a condominium and / or environment represented in Figure 3; Figure 7 shows a possible frequency subdivision of the signals used for the second variant mode represented in Figure 6; Figure 8 shows a third variant mode of the distribution system of a plurality of signals in a condominium and / or community environment represented in Figure 3; Figure IA shows schematically the spectrum of frequencies used for the distribution of signals; specifically, the 40 MHz band is coupled to the CATV (Cable TV, ie Cable TV) return channels for the exchange of communication between the user and the service provider; the 47-68 MHz and 174-230 MHz bands contain the television channels belonging to the first VHF band and the third VHF band, respectively; UHF television channels are distributed in the 470-862 MHz band. Both bands of 110-174 MHz and 230-445 MHz are partially used to distribute CATV channels and converted to satellite channels. The 230-445 MHz band is also known as an extended S-band. The VHF bands are subdivided into 7 MHz channels, while the UHF and CATV channels are 8 MHz, as shown schematically in Figure 1C. Figure IB shows schematically a particular use of the spectrum within the range of 41-46.5 MHz, which is described below. Figure 2 shows a known system for receiving and distributing signals. The number 1 indicates a set of antennas for receiving VHF and UHF signals amplified by means of channel amplifiers, represented in block 2, and subsequently sent to a mixer 3 and subsequently distributed. The number 4 indicates an antenna for the reception of satellite signals, which are notoriously in the band around 12 GHz in 27 MHz amplitude channels, with a modulated FM carrier. Block 5 represents a so-called LNB (Low Noise Block, that is, Block with Low Noise) of the universal type, which amplifies and converts the first intermediate frequency of 0.950 - 2.050 GHz, the analog and digital signals into channels of 36 The block 6 reveals the FM signals, which are thus remodulated in AM, and converted into VHF, UHF or S-band channels extended by the block 7. Then the signals are sent to the mixer 3 and subsequently distributed. The lines indicated with the number. 8 represent the entrances to the various apartments consisting of a coaxial cable; the number 9 indicates the signal plugs available in the apartments, while the number 10 indicates a user terminal, in the specific example, a television receiver that can be operated by a remote control 11. Figure 3 represents a distribution system of a plurality of signals in a condominium and / or community environment in accordance with the present invention, where the possibility of receiving both analogue television signals and the new digital signals is considered. It will be noticed that the blocks indicated with the same reference number in figures 2 and 3 perform the same functions; thus, blocks 4 and 5 are used to receive analog and digital signals from satellite. In Figure 3, blocks 6 and 7 shown in Figure 2, specifically related to analog signals, are omitted for reasons of clarity. In the diagram shown in Figure 3, three different types of digital television signals received are indicated; however, the following description applies to any digital signal, such as the DAB signal (Digital Audio Broadcasting, ie Digital Audio Broadcasting) for digital radio broadcasting, or a signal containing data, or a video signal in general. The terrestrial digital television signals are received by means of the set of antennas 19, which comply with the specifications of the DVB (Digital Video Broadcasting) have the COFDM modulation (Coded Orthogonal Frequency Division Muí t iplexing) and are transmitted by the same system of channel for the analog signals VHF and UHF.

Block 14 receives, via a coaxial cable 14 ', the CATV digital signal, which is modulated in QAM (Quadrature Amplitude Modulation, ie, Quadrature Amplitude Modulation) in 8 MHz channels, whereas as mentioned above, antenna 4 receives digital signals from satellite, which are modulated by QPSK (Quadrature Phase Shift Keying, that is, Change in the Quadrature Phase Key). It will be appreciated that the previous digital signals, terrestrial, satellite and cable, are modulated in different modes (COFDM, QPSK, QAM respectively), so that to use them requires the three different types of demodulators. Typically, the transmission of either of the two modulated QAM or QPSK digital signals is performed under SCPC procedures (Single Channel Per Carrier, that is, a Solo Channel Per Carrier), while the transmission of digital television signals that are provided by the DVB (Digital Video Broadcasting) standard is presented under the MCPC (Milti Channel Per Carrier) procedure. At the entrance of each apartment or building, a band-stop filter S is connected, in series with the distribution cable, which is represented by the block 15, that is, a filter that blocks the passage of the signals that are included within. of a predetermined band, in this way its reception inside the apartment or building is hindered. Therefore, this band is a band reserved within the distribution in a condominium and / or community environment, which inhibits all users who do not wish to receive the new signals. Obviously, to ensure the previously existing service, all analog signals have to be distributed in non-compressed channels in the previous reserved band, and this can be easily obtained using the known technique of frequency conversion. It is clear that the previous reserved band may consist of several parts, and in this case the filter 15 inhibits the signal flow in several bands, for example in the extended S-band and the 110-174 MHz band. To avoid possible interference , it is appropriate to have the band stop filter also inserted in the output of block 2. The system in this modified manner, represents the basic structure for the subsequent implementations. In fact, one or more users must decide at a certain time to have access to the new digital signals, so that each user has installed the following devices, which are added without modifying the existing system. 1. A circuit for the previous selection of transponder, indicated in figure 3 by block 12, for the selection of one to four bands existing in the LNB (high band, low band, horizontal polarization and vertical polarization that is, high band , low band, horizontal polarization and vertical polarization). As is known, the transponder is a frequency amplifier and converter device, which radiates signals from a satellite. 2. A QPSK / QAM transmodulator, indicated by block 13, which selects the digital signal from the satellite, demodulates it, remodulates it into QAM and converts it into a predetermined channel for the use of only one user among those who have accepted the implementation of the system (preferably, a personal channel that is included in the previous reserved band); this channel preferably has a bandwidth of 8 MHz. The signal is subsequently sent to the mixer 3. Substantially, the reserved band is subdivided into a plurality of channels that are available to the users who wish to receive the new signals.

A COFDM / QAM transmodulator, indicated by block 20, which selects a digital terrestrial television signal, demodulates it, modulates it in QAM, converts it into the reserved channel above and sends it to the mecifier 3.

A block 14, which selects the CATV digital signal, converts it into the personal channel above and sends it to the mixer 3.

A selective channel-pass filter, indicated by block 16 which, arranged in parallel with the band stop filter, allows the user to receive his own personal channel. The + symbol indicates a signal adder.

A QAM demodulator, which may be contained in an appropriate module, or belong to the decoder-r eceptor IRD (Integrated Receiver Decoder, that is, Decoder with Integrated Receiver) with reference number 18, as indicated in Figure 3.

A user terminal indicated by block 17, which represents the interface between the distribution system and the user. By means of said terminal the user is able, by means of the operation in the modules 12, 13, 14 and 20, to select the source and the desired channel to be sent to the personal channel, and to adjust the various parameters, such as the type of satellite, the polarization of the signal, QAM signal level, sending the appropriate controls through a return channel, as described below If, for example, if the reception of a specific digital channel from a satellite is desired, the user will operate the previous selector 12 for choosing the band and allowing the output of the block 13 towards the mixer 3, while the output of the blocks 14 and 20 towards the mixer are held in lock (locked). The user terminal 17 may be either a separate block or, as in FIG. 3, communicate with the IRD receiver indicated by block 18, whose QAM demodulates the digital signal, decodes it and sends it to the television not shown in the figure. In this example, the user terminal and the IRD receiver can be controlled by the same remote control 11.

A channel-return module, which can be included in the terminal of the user 17 as shown in figure 3 and allows the user to control the blocks 12, 13, 14 and 20. In case of low bit rates, ie 9.6 Kbits / s and multiples up to 48 Kbits / s, you can use any of the two modulations, the FSK (Frequency Shift Keying) or the PSK (Phase Shift Keying), which are distributed to a channel of 128 KHz of amplitude, to have the same minimum bandwidth as provided by the DVR-RC standard in the channel - regre so. Higher bit rates must be requested, then the 18 KHz multiple band amplitudes can be used as provided in that standard, which are within the range of a minimum of 256 Kbits / s of bit rate with a band of up to 128 KHz 3.088 Mbits / s with a band of 1.544 MHz using QPSK modulation, and up to 12.8 Mbit / s with a 3.2 MHz band using QAM modulation 16. The information that is sent on the return channel may eventually go further there that the respective transmodulator and sent out of the building in many ways (telephone line, satellite, etc.).

The control instructions for the transmodulator can use packets as provided in the DVB-RC standard. The return channel can be distributed to the frequency band directly below the band of the television channels, for example within the range 41-46.5 MHz according to the European standard B, as shown in figure IB. Said return channel may be a bidirectional channel, that is, a transmodulator, once a control from the terminal of the user 17 is received, can answer by giving the user terminal 17 the confirmation of the operation performed, or by supplying other data such as is required In any event, it is also possible for the transmodulator to initiate a communication on the channel, back, for example when the installer is in the attic and wants to change some parameters of the IRD receiver 18. The bidet communication is performed 1 under the TDMA procedure (Time Division Multiplexing Access, that is, Multiplex Access for Time Division). Obviously, each user will have their own personal return channel. Selling carefully, this signal can be sent through the common distribution coaxial cable of the system. By means of the system described above, a single user can, together with the analog signals, also have in his apartment a digital signal of his own choice containing from 4 to 6 programs, of which each can be received from an IRD in an independent mode To have simultaneous availability of two digital channels, another personal channel is also required with its associated transmodulator and channel pass filter to be installed; of course the availability of at least two IRDs is also required. The system for the distribution of a plurality of signals in a community and / or condominium described above offers a high flexibility and can freely accept subsequent gradual implementations, without causing any conflict with the rules governing the condominium or community. The system for the distribution of a plurality of signals in a condominium and / or community environment in accordance with the present invention offers the additional advantage that the same wired system can also be used for analog signals for the distribution of the new signals, it is say, without requiring a new wiring arrangement.

On the other hand, the only user only requires a demodulator for the digital signals, as these signals in their entirety are remodulated by QAM before distribution. In addition, such demodulation drastically reduces the problems of interference, int ermodul ation and signal equalization, which usually occur in the case of a multiple standard distribution.

The signal distribution system shown in figure 3 requires installation, for each new user who wants to have access to the new digital signals (for example those irradiated by satellite), of an appropriate transmodulator 13 for each signal that belongs to a standard different, said transmodulator 13 comprises at least one tuner for the selection of the signal, a demodulator, a QAM modulator and a frequency converter.

In view of the costs, it will be noted that for each user an equal number of transmodulators is required, together with the number of digital signals with different standards to be received. Therefore, in Figure 4 the diagram of a variant mode of the distribution system of a plurality of signals in a condominium and / or community environment, comprising a modi fi ed transmodulation device is shown. In the embodiment of Figure 4, instead of sending each digital signal to a different transmodulator 13, 14, or 20, the digital signals are sent to a single "universal" transmodulator, represented by the block 29; the remaining blocks shown in figure 4 with the same reference number have the same functions as the blocks already mentioned in figure 3. As can be seen, figure 4 shows three different types of digital television signals received; however, the following description applies to any digital signal, such as the DAB signal (Digital Audio Broadcasting, ie, Digital Audio Broadcasting) for digital radio broadcasting and / or a signal that includes data and / or signals of video in general.

Once the transmodulators 13, 14 and 20 of Figure 3 are replaced by the transmodulator 29 of Figure 4, the remaining portion of the distribution system of a plurality of signals in a condominium and / or community environment will operate in the same way .

In figure 5 a way is provided to provide the block 29, wherein the block 30 represents a tuner for the selection, in the range 950-2150 MHz, digital satellite channels modulated in QPSK and appropriately preselected in the block 12; the digital channel selected in block 30 under user control is subsequently demodulated by a QPSK demodulator represented by block 31.

Block 32 represents a tuner for the selection of digital channels modulated in QAM received by the cable in the range 5-862 MHz; the digital channel tuned by block 32 under user control is subsequently demodulated by means of a QAM demodulator represented by block 33. Block 34 represents a tuner for the selection, in the range 47-862 MHz, of digital terrestrial channels modulated in COFDM, the digital channel tuned by the block 34 under the control of the user is subsequently demodulated by a scrambling COFDM i by the block 1 35. Block 36 represents a switch, which receives the demodulated digital signals in the demodulators 31,33 , 3.5; at the exit of block 36 one is represented! of these three signals I selected by the user through block I 17. The signal is modulated again in QAM by means of a QAM modulator, represented by block 37, and then converted by a converter represented by block 38 in the aforementioned personal channel for the exclusive use of a single user, which is comprised in a frequency band in the range of 47 to 862 MHz, preferably 230 to 445 MHz. Therefore, each user I is the owner of a universal transmodulator 29, which contains a converter with a fixed frequency output channel for its own personal use. The signal is subsequently sent to the mixer 3 to be distributed as previously described. It will be noted that the demodulation and remodulation of the QAM signal, which are apparently superfluous operations, are performed to recover the bit error rate that is eventually introduced by the cable distribution. It will also be noted that the system continues to provide a "return channel" module, which may be contained in the user's interface or terminal 17, which allows the user to send a selection control signal to the subscribers themselves. blocks 12, 30, 32, 34 and 36 using a signal that is preferably FSK or PSK, distributed to a channel, for example within the range of 41-46.5 MHz. Selling this signal can be sent through the coaxial cable , common, system distribution. As may be assumed from the above description with reference to Figure 5, by appropriate grouping of the various specific functions within a single device, ie the transmodulator 29, it is then possible for each individual user to use only one modulator 37 and a converter 38, instead of the three modulators and the three converters as described with reference to figure 3. It will also be noted that the former universal transmodulator 29 which can advantageously be used for both, for a distribution system of signs in a condominium and / or community environment and in the example of a single system. The various parts of the universal transmodulator 29, that is, the selection means 30,32,34,36, the demodulation means 31,33,35, the demodulation means 37 and the conversion means 38, can obviously be accommodated in a same housing, with clear practical advantages, also in view of the installation of the system and the reduction of the components that compose it. The system for the distribution of a plurality of signals in a condominium or community environment represented in figure 3 and 4, operates only in the so-called downstream signal, that is, the signal received by the provider or broadcaster, while this does not allow the user to transmit an upstream signal to the provider.

Therefore, Figure 6 represents the diagram of another variant embodiment of the distribution system of a plurality of television signals in a condominium and / or community environment shown in Figure 3. In this figure, the blocks related to both are omitted. television signals, that is, digital and analogue; on the other hand, the remaining blocks of figure 6, which indicate the same reference number, have the same function as the blocks already shown in figure 3.

In comparison with figure 3, figure 6 shows five new blocks indicated with the reference numbers 40, 41, 42, 43 and 44, respectively, which are described in more detail below.

Block 40 represents a terminal, used by the user to transmit the upstream US signals and receive the downstream DS signals, which is connected directly to the interface 17 previously described with reference to figure 3. Said terminal 40 performs the following known functions: - the function of a personal computer, to elaborate US signals upstream to transmit them and the reception of DS signals downstream; the coding function, for the coding of upstream US signals to be transmitted; the function of the QAM modulator, to modulate US signals upstream to be transmitted; - the function of a QAM type tuner SCPC, for receiving DS signals downstream; the function of the QAM demodulator, to demodulate the DS signals downstream; - the decoder function, for decoding the received downstream DS signals.

The downstream DS signals that are received and the upstream US signals that are transmitted by the block 40 are distributed to the previous personal channel, for the exclusive use of the user, as explained below. The distribution system of a plurality of digital signals in a condominium and / or community environment uses the satellite to send the signals back to the provider. Therefore, upstream signals US are sent, via interface 17, filter 16, cable 8 and mixer 3, from block 40 to an SCPC transmodulator indicated by block 40. The latter, which demodulates said upstream US signal according to the QAM coding, remodulates it according to the QPSK coding according to the SCPC procedure, then converts said upstream US signal to a frequency that is compatible with the frequencies available on a satellite channel, and finally send it to antenna 4 for transmission to the satellite. The downstream signal DS that is received by the antenna 4 is sent to a transmodulator 42 which, in addition to the function belonging to the block 13 of figure 3, also operates as a tuner for the multimedia signals modulated by QPSK in accordance with the SCPC procedure, which is received from a satellite channel; as a result the downstream DS signals that are received in block 42, once the reception of an appropriate control sent by block 40 is received, a QPSK is demodulated under the SCPC procedure, remodulated in QAM coding and converted in the signal DS downstream reaches block 40, through mixer 3, cable 8, filter 16 and interface 17. If the system distributing a plurality of digital signals in a condominium and / or community environment uses transmission by cable, the current US signal, above is sent via block 40, through blocks 17,16 and 8, to mixer 3, and subsequently to an SCPC transmodulator indicated by block 43. Here, the. US signal upstream becomes a frequency band compatible with the frequencies associated with the cable channel; Subsequently, the upstream US signal is sent to the service provider via the coaxial cable 14 '. The downstream US signal, on the other hand, is selected by the transmodulator 44, together with the functions performed by the previously described block 14, tunes the downstream DS signal which is modulated by QAM under the SCPC procedure and converts it into a band. frequency that corresponds to the personal channel band above. The DS signal downstream then reaches block 40 via blocks 3.8 16 and 17.

Blocks 41 and 42 can advantageously be housed in the same device; the same applies for blocks 43 and 44, which can also be housed in a single device. Even more advantageously, all the blocks 41, 42, 43 and 44 can all be housed together in a single device. In figure 7, the distribution of the upstream US signals in the DS signals downstream in the personal channel is shown, where the shaded line SI indicates the frequency band of the personal channel, normally at an amplitude of 8 MHz; the solid line S2 represents the band occupied by the signal DS downstream, to which a carrier f l f is associated while the line S3 represents the band of the upstream US signal, to which a carrier f2 is associated. Figure 7 also shows some frequency distributions of the return channel modulated by FSK or PSK, which is used to, as mentioned above, control the blocks of the distribution system through the interface 17. In particular, the return channel above it can be located in an area not occupied by upstream US signals and downstream DS signals, as indicated by reference number S5, or in an area where the frequency response of the personal channel is gradually reduced to zero, that is, an area called rolling, as indicated by the reference number S4. If the upstream US signals and the downstream DS signals are simultaneously available in the personal channel, that is, when the system operates with frequency multiplexing (FDMA procedure, i.e. Frequency Multiplex Access), it is clear that the bands S2 and S3 should not overlap. On the other hand, if the upstream US signals and the downstream DS signals are available at different times in the personal channel above, then a time multiplexing operation is performed (TDMA procedure, i.e. Time Division Multiplex Access ).

Obviously, when the personal channel is used to receive digital television signals and / or audio signals and / or data signals, the user disables the blocks 40,41,43 through the interface 17 and the return channel, and change blocks 42 and 44 to the functions already described for blocks 13 and 14, respectively.

Figure 8 shows the diagram of a further variant mode of the distribution system of a plurality of digital signals in a condominium and / or community environment according to the invention. In figure 8, the blocks having the same reference numbers perform the same function of the blocks already represented in figure 3.

In figure 8 a new block indicated with the number 51 is shown, the place of the block 18 illustrated in figure 3, which represents an IRD receiver able to read one or more smart cards 52, as it is better detailed below. Each broadcaster or provider chooses to pay for their own conditioned access system, and therefore the accessories, receiver 51 and smart card 52 are necessary for vision, which are usually supplied by the same broadcaster. According to the present invention, a member of a condominium must decide to make a subscription, for example, to pay for channels irradiated by satellite, in addition to the devices already provided for the reception of digital channels from a satellite (ie, a preselector circuit). of transponder 12 and a QPSK / QAM transmodulator 13, which generates its own channel for exclusive use), the user may also need receiver 51; said receiver, in addition to the demodulation in QAM and decodes the signal, also has to perform the required deconfiguration to make the signal useful in itself. To perform the last operation, the receiver 51 has to be adjusted to a reader capable of reading the information associated with the smart card 52, which contains the necessary electronic key that allows the use of the interactive services by means of the deconfiguration. In addition to the information required to allow the conf igur ation in the receiver 51In addition, the information necessary for the transmodulator QPSK / QAM 13 and the transponder preselector 12 for tuning in the channels the transmission for payment of programs are inserted in the smart card 52. The tuning information comprises in particular the frequency of the channels to be inserted into the personal channel, where said information has to be sent to the transmodulator 13; said information further comprises the polarization type (horizontal or vertical) bit rate and frequency band (high or low) of the signals to be received, which have to be sent to the transponder preselector circuit 12. The receiver 51 transfers the information from up, through the return channel, to the transponder preselector 12 and the transmodulator QPSK / QAM 13, which in this way can be tuned to the channels allowed by the smart card 52.

Obviously, mutual interaction between the receiver 51 and the associated smart card 52, the transponder preselector 12 and the transmodulator QPSK / QAM 13 will be allowed, and this is obtained by an appropriate programming of the microprocessors controlling the aforementioned devices. For this reason, the receiver 51 and the associated smart card 52, the transponder preselector 12 and the transmodulator QPSK / QAM 13 are usually manufactured and supplied as a whole, usually on an income basis, by means of the broadcaster transmitting the programs. of pay In order to prevent the user from eventually using the QPSK / QAM transmodulator from above also to receive pay channels transmitted by other broadcasters, a "programmed electronic key" is inserted by the installer into the QPSK / QAM 13 rasmodulator. in such a way that the smart card 52 is inserted in the receiver 51, the transmodulator QPSK / QAM 13 can only be tuned to the channels allowed by the smart card 52 associated with the broadcaster supplying the devices. different intelligent that does not contain the same programmed electronic key is inserted into the transmodulor 13, the operation thereof (the transmodulator) is inhibited.The insertion of said programmed electronic key, ie an appropriate digital signal, can for example be provided using a port serial of the microprocessor controlling the QPSK / QAM 13 transmodulator, such a port is accessible through a separate connector e the outside of the transmodulator QPSK / QAM 13. Obviously, if the smart card 52 is not inserted in the receiver 51, the system can be tuned to any free access channel. Additionally, in view of protecting the privacy of more condominium users who subscribe to the same program, the system according to the invention allows the frequency of a personal channel to be inserted, for example by the installer, in the smart card 52 of each user, so that the receiver 51 will only receive the signals in said personal channel. Thus, even if any user can receive the personal channel of another user in his own receiver 51, for example by altering the channel-passage filter 16, said receiver 51 controlled by the smart card 52 can not proceed to deconfigure and decode. The above situation can easily be extended to a situation where the pay channels are transmitted by cable, that is, the digital CATV (Cable TV, ie cable television) channels modulated in QAM that are received by the coaxial cable 14 '. or by terrestrial television signals modulated in COFDM (Orthogonal Coding Frequency Division multiplexing) that is received by the antenna 19. In such circumstances, the smart card 52 contains the tuning information for the respective modulators 14 and 20. It is obvious that many system changes are possible according to the present invention, without departing from the novelty spirit of the inventive idea. For example, the return-channel can be radiated at radio frequency, instead of being transmitted by cable; in this case, the blocks 12, 13, 14 and 20 have to be equipped with the known radio frequency reception devices.

Additionally, block 14 can offer the possibility of demodulating and remodulating the QAM signal, to recover the bit error rate introduced by the cable distribution.

In addition, the distribution to single buildings or departments can be obtained in a "wireless" configuration, that is, without cables, using networks known as MMDS (Multiple Point Distribution System for Multiple Channels) and LMDS (Local Point Distribution System). ). Also in this example, the signals coming from several sources are received by a single equipment, which consists for example of blocks 1,2,3,4,12,13,14,19,20, of figure 3; the signal that leaves the mixer is subsequently converted to high frequency (up to 40 GHz) and then irradiated. The signals are received by known receiving devices in several buildings or in individual departments, they are converted within the range 47-862 MHz and subsequently distributed by means of cable as is given in the output of the mixer 3 shown in figure 3. The presence of the band-stop filter 15 can also be used not only for the filtering of the signals distributed by the system, but also for filtering the signals that are possibly eventually available in a distribution network within a department. In fact, the networks of home distribution of radio and television, information, operation and control signals are known, which often use the same physical medium used for the distribution of the radio and television signals that are received from satellite, cable or antenna. Therefore, an appropriate configuration of the band-stop filter 15 will prevent the signals coming from inside the department and being picked up by other users of the system. Moreover, if the CATV signal has a low bit error ratio, the block 33 will be omitted in the universal transmodulator 29; in this example the signal goes directly from the tuner QAM to the switch 36; in this case, the last one needs to go directly to the converter 28, which has to be used to select the QAM channel. On the other hand, the tuners 30,32,34 or at least two of them, can be integrated in an extended band tuner, for example from 5 to 2150 MHz, which contains within the appropriate filters and change devices for selection of the input signal. The demodulators 31,33,35, or at least two of them, can be obtained in an integrated circuit; similarly, also blocks 31,33,35,36,37 can be obtained in a single integrated circuit. The user terminal 17 may be a separate block, or be contained in the QAM tuner of the IRD receiver 18. In addition, the place of using the cable or satellite as described above for both upstream and downstream signals, the Upstream channel can be sent through the cable and downstream signals are received from the satellite, or vice versa. On the other hand, the upstream signal, which as it was already said is usually transmitted with a low bit rate, can be sent by telephone with the help of a modem connected to block 40, according to well-known techniques. Moreover, the SCPC transmodulators may comprise a device for storing step data commonly known as a buffer, where incoming upstream signals are stored; the signals are sent when the store is substantially completely filled by the signals. In this example, the upstream signals can enter from more personal channels, for example when a number of users agree to use a single SCPC transmodulator for sending the signals for example, by satellite. For example, tuning the information contained in the smart card can be changed by the broadcaster, this because the frequency of the transponder has changed, or new services have been acquired by the user, or the mode of transmission of services has changed , for example, from MCPC or SCPC or vice versa. In this example, the receiving devices automatically adjust the situation by means of the instructions received from the smart card. The new data can be sent with the help of a modem, which is usually incorporated into the receiver, or through the so-called Service Information (IS), that is, the service information that is expressly inserted into the transmitted digital signal. It is clear that the receiver has been equipped with a writing device, among those known in the technology, for the insertion of data in the EEPROM memory of the smart card. It is noted that in relation to this date, the best method known to the applicant, to carry out the aforementioned invention, 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 (51)

1. A system for distributing to a condominium and / or community environment, a plurality of digital signals that are transmitted according to different standards, said digital signal is distributed together with other information signals, comprising means for receiving said digital signals, means for the frequency conversion of the digital signals, means for mixing or combining all the information signals in a distribution network that feeds a plurality of sockets or sockets for signal, connected to the receivers, among which at least a part has the purpose of receiving the digital signals, characterized in that the means for converting the frequency of the digital signals comprises means for the demodulation of the digital signals having different transmission standards and means for remodulating the digital signals with a single type of digital modulation ( QAM), providing the digital signals with a single modulation type (QAM) to the means for mixing the information signals in the distribution network, and because the receivers that have the purpose of receiving the digital signals are adjusted to decode such a unique type of modulation (QAM).

2. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that such a unique type of modulation (QAM) is Quadrature Amplitude Modulation.

3. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the means for converting the frequency of the digital signals are means for converting the frequency of one or more reserved digital signals that are received in portions. reserved frequency, or personal channels, these personal channels are reserved for the corresponding inputs or predetermined plugs, and prohibited for the remaining inputs or plugs with the help of the media, thereby allowing access to such personal channels of the only band corresponding to the inputs or signal plugs, these means for converting the frequency of one or more digital signals received in the personal channels of the band that is commanded by the respective means of control of the user.

4. A system for distributing to a condominium and / or community environment according to the indication 1, characterized in that the distribution network of the information signals comprises a distribution support made by means of a coaxial cable.

5. A system for. distributing to a condominium and / or community environment according to claim 1, characterized in that the distribution network for distributing said information signals comprises MMDS and / or LMDS networks.

6. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the personal channel is of an amplitude of 8 MHz.

7. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the personal channel is included in a frequency band that is between 47 and 862 MHz.

8. A system for distributing to a condominium and / or community environment according to claim 7, characterized in that the ranges of the frequency band are preferably within 230 to 445 MHz.

9. A system for. distributing to a condominium and / or community environment according to claim 1, characterized in that the means for accessing said personal channels comprise means for filtering the personal channel, which are located in the upstream of the inlet or plug the signal .

10. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the means for filtering comprises a band-stop filter, capable of eliminating the reception with the help of the plug or signal input.

11. A system for distributing to a condominium and / or community environment according to claim 10, characterized in that the filtering means further comprises, in correspondence of a predetermined plug or signal input, a channel passage filter is arranged in said filter Stop-signal, which allows the personal channel to pass through a single user

12. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the selection of the digital signal to be converted in said personal channel is made through a return channel.

13. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return-channel is modulated in FSK.

14. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel is modulated in PSK.

15. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the channel -regression is modulated in QPSK.

16. A system for distributing to a condominium and / or community environment according to the indication 12, characterized in that the return channel is modulated in QAM.

17. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel is bidirectional low in TDMA procedure.

18. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel has a bandwidth of 128 KHz or multiples thereof.

19. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel is comprised between 41 and 46.5 MHz.

20. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel uses the same coaxial cable of the distribution network of the system.

21. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel used by a user is not accessible to the other users of the system.

22. A system for distributing to a condominium and / or community environment according to claim 12, characterized in that the return channel is radiated by radio frequency.

23. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the selection, modulation and frequency conversion in a predetermined channel of the digital signals are obtained by means of a transmodulator.

24. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that a user terminal and an IRD-type receiver-decoder are provided, which can be operated with the help of the same remote control.

25. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that two or more selection means are included in a single transmodulator device.

26. A system for distributing to a condominium and / or community environment according to claim 25, characterized in that a single transmodulation device comprises means for tuning, which are capable of performing the selection of said digital signals within at least two ranges of frequency, and demodulation means, which are capable of demodulating at least two of said signals transmitted with different standards.

27. A system for distributing to a condominium and / or community environment according to claim 26, characterized in that the transmodulator device includes at least two tuners for the selection of the digital signals, and at least two demodulators of said digital signals.

28. A system for distributing to a condominium and / or community environment according to claim 26, characterized in that the transmodulator device further includes a switch capable of receiving the digital signals coming from said demodulators.

29. A system for distributing to a condominium and / or community environment according to claim 26, characterized in that the transmodulator device further comprises a modulator for remodulating the output signal of the switch.

30. A system for distributing to a condominium and / or community environment according to claim 25, characterized in that the transmodulator device further includes a converter for converting the output signal of the modulator into a predetermined channel in frequency.

31. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the control means are also capable of generating one or more digital signals in transmission or upstream (US) signals and converts them into frequency in the personal channel, and the second selection and the handling means are provided for said digital signals in transmission, all means for the transmission of said upstream (US) signals from satellite or by cable.

32. A system for distributing to a condominium and / or community environment according to claim 31, characterized in that the means for transmodulating and the second selecting means operate on the received downstream signals or on the upstream (US) signals modulated under the SCPC procedure, respectively.

33. A system for distributing to a condominium and / or community environment according to claim 31, characterized in that the personal channel that can be accessed by the user is only used under the FDMA procedure, that is, the upstream (US) signals. and the downstream signals (DS) are simultaneously present in the same personal channel.

34. A system for distributing to a condominium and / or community environment according to claim 33, characterized in that said personal channel both signals, those of upstream (US) and those of downstream (DS) do not occupy overlapped frequency bands.

35. A system for distributing to a condominium and / or community environment according to claim 31, characterized in that the personal channel is used under the TDMA method, ie the upstream (US) signals and the downstream (DS) signals are not present simultaneously in the personal channel.

36. A system for distributing to a condominium and / or community community according to claim 34, characterized in that the selection means and the second selection and management means are included in a single housing.

37. A system for distributing to a condominium and / or community environment according to claim 3, characterized in that the user control means comprises a receiver capable of performing an access function to a plurality of conditioned access services, reading the information contained therein. in a smart card, and said information contained in the smart card controls the means for frequency conversion of one or more reserved digital signals that are received in the personal channel.

38. A system for distributing to a condominium and / or community environment according to the indication 37, characterized in that the information contained in the smart card comprises information for the tuning of the transmodulators.

39. A system for distributing to a condominium and / or community environment according to claim 37, characterized in that the information contained in the smart card comprises information for tuning the pre-selection means of the transponder.

40. A system for distributing to a condominium and / or community environment according to claim 40, characterized in that the information for tuning the pre-selection means of the transponder is information selected from the bands of the channels to be tuned.

41. A system for distributing to a condominium and / or community environment according to claim 38, characterized in that the information for tuning the pre-selection means of the transponder is information to determine the polarization of the channels to be tuned.

42. A system for distributing to a condominium and / or community environment according to claim 38, characterized in that the information contained in the smart card comprises frequency information of the channels to be tuned.

43. A system for distributing to a condominium and / or community environment according to claim 37, characterized in that the information contained in the smart card further comprises the frequency information of said personal channel.

44. A system for distributing to a condominium and / or community environment according to claim 37, characterized in that the selection means and the smart card contain respective electronic keys, whose congruence allows the operation of said distribution system of a plurality of signals to a condominium and / or community environment.

45. A system for distributing to a condominium and / or community environment according to claim 37, characterized in that the control means contains a device for writing data in a programmed memory of a microprocessor included in the card int el i gente.

46. A system for distributing to a condominium and / or community environment according to claim 45, characterized in that said programmed memory is in an EEPROM type memory.

47. A system for distributing to a condominium and / or community environment according to claim 45, characterized in that the device for writing data in a program memory of a microprocessor is included in the smart card that operates by sending the data to the media of control with the help of a modem.

48. A system for distributing to a condominium and / or community environment according to claim 45, characterized in that the device for writing data in a program memory of a microprocessor that is included in the smart card, which operates by sending the data to the means of control of the Service Information that is included in the received digital signal.

49. A system for distributing to a condominium and / or community environment according to claim 1, characterized in that the means to allow access are able to prevent the passage of signals generated within an additional distribution network associated with an input or plug , in particular it is inside a house or apartment.

50. A method for distributing to a condominium and / or community environment a plurality of digital signals together with other information signals, at least some of the digital signals is reserved for a predetermined plug in the environment, comprising the steps of : - receiving said digital signals, operating a frequency conversion of the received digital signals, mixing the digital signals in a distribution network that distributes the digital signals to the sockets, characterized in that: in the step of the frequency conversion of the digital signals received, the received signals are demodulated, and subsequently re-modulated with a single type of signal modulation, and then mixed with other information signals in a common signal in the distribution network, from which it is distributed to the receivers for decoding adjustment in said single type of digital modulation.

51. A method for distributing to a condominium and / or community environment a plurality of digital signals, characterized in that the only type of digital modulation is Quadrature Amplitude Modulation. SUMMARY OF THE INVENTION The present invention relates to a system for the distribution in a condominium and / or community environment of a plurality of television signals, and / or audio signals, and / or digital audio and / or video signals transmitted with different standards. According to the invention, one or more digital signals can be received by a simple user of the system by means of a frequency conversion of a predetermined channel, which can only be accessed by said user. In addition, the digital signal is present in said channel always having the same modulation and can be selected by said user through the control means which sends a control signal to the selection means.