ITTO980967A1 - PLANT FOR THE CONDOMINIUM AND / OR COMMUNITY DISTRIBUTION OF A DIGITAL SIGNALS LENGTH. - Google Patents

Description

Description of the industrial invention entitled:

"PLANT FOR THE CONDOMINIUM AND / OR COMMUNITY DISTRIBUTION OF A PLURALITY OF DIGITAL SIGNALS"

SUMMARY

System for condominium and / or community distribution of a plurality of television signals and / or audio signals and / or digital audio and / or video signals and / or data transmitted with different standards, these signals being defined as downstream signals (DS), comprising means (1, 4, 14, 19) for receiving said downstream signals (DS), where one or more digital signals can be received by a single user of the system by means of a frequency conversion in a predetermined accessible channel only to the aforementioned user, the digital signal present in the aforementioned channel being selectable by the aforementioned user through control means (11, 17, 18, 20) which send a command signal to selection and processing means (12, 13, 14, 20 , 22, 24). According to the invention, the control means (11, 17, 18, 20) are also able to generate one or more digital signals in transmission or upstream signals (US) and convert them into a frequency in the predetermined channel accessible only to the aforementioned user. and second selection and processing means (21, 23) of said digital signals in transmission are provided, and means (4, 14 ',) for the transmission of said upstream signals (US) over the air and / or from satellite and / or cable.

DESCRIPTION

The present invention refers to a condominium and / or community distribution system of a plurality of television signals and / or audio signals and / or digital audio and / or video and / or data signals.

With the advent of digital technology, so-called multimedia systems are spreading more and more, in which communication between user and service provider starts in a bidirectional way, i.e. the user can both send information, an operation known as upload, and receive information. known as a download, from the information provider or service provider. The information, which includes data, images and sounds, is sent via digital signals with QAM (Quadrature Amplitude Modulation) modulation for cable transmissions or QPSK (Quadrature Phase Shift Keying) for satellite transmissions; to carry multimedia signals in general, the use of the telephone line is also suitable, but for applications that require high data transmission speeds, i.e. high bit rates, it is necessary to resort to cable and / or satellite, means that allow the use of bands frequency so as to speed up the data flow. The transmission of both QAM and QPSK modulated multimedia signals typically takes place in SCPC (Single Channel Per Carrier) mode, while the transmissions of digital television signals envisaged by the DVB (Digital Video Broadcasting) standard are typically in MCPC (Multi Channel Per Carrier) mode. As is known, the MC.PM mode provides that in a transmission channel, for example a channel with QPSK modulation from a satellite of 36 MHz of bandwidth, there is only one carrier modulated by a stream of digital data (the so-called Transport Stream) belonging to multiple programs; in the SCPC mode, on the other hand, one or more carriers are allocated in a channel, each of which is modulated by a signal belonging to a single program. The modulated carriers occupy a frequency band proportional to the bit rate of the modulating digital signal; naturally the various bands present must not overlap in order not to create serious problems in reception.

With reference to the user, the signal sent to the Service provider is known as upstream, i.e. sent upstream, while the received signal is known as downstream, i.e. received downstream. Normally the upstream signal has a lower bit rate, and therefore a bandwidth, lower than the downstream signal.

For a user who lives in a single house and wishes to take advantage of a multimedia transmission system, there are no particular difficulties, it is sufficient to acquire and install the necessary equipment for transmission and reception available on the market and make the necessary connections. On the other hand, problems may arise if the user lives in a condominium or in a community; in these cases, in fact, the installation of new systems and equipment must take place following the condominium regulations, and, in any case, with the consent of the majority of the condominiums, in many cases difficult to obtain.

In the Italian patent application T098A000048 in the name of the same applicant, a system is indicated that allows the distribution in a condominium and / or community area of a plurality of digital television and / or audio signals, regardless of the type of standard of the signals received, and which it allows a gradual implementation of the distribution system linked to the free decision of each individual user to increase the degree of sophistication of their receiving apparatus. Reference must be made to the aforementioned Italian patent application for all the parts common to the present invention and not explained in detail below. The aforementioned system provides that each user can have a personal channel of his exclusive use, through which he can receive normal digital television signals and / or audio and / or data signals.

Said distribution system in the condominium area of a plurality of digital signals operates only on the downstream signal, i.e. the received signal, while it does not allow the user to operate by transmitting an upstream signal, thus losing the advantages of interactive multimedia and communications with the provider .

The purpose of the present invention is to indicate a system for the condominium and / or community distribution of a plurality of television signals and / or audio signals and / or digital audio and / or video and / or data signals which, overcoming the aforementioned drawback, allows each user to use said digital signals in a bidirectional manner using his own personal channel that may already exist in the system, and without compromising the service already provided by the system.

To achieve this purpose, the present invention relates to a condominium and / or community distribution system of a plurality of television signals and / or audio signals and / or digital audio and / or video signals and / or data transmitted with different standards. or downstream signals having the characteristics described in the attached claims, which form an integral part of the present description.

Further objects, characteristics and advantages of the present invention will become clear from the detailed description that follows, and from the attached drawings, provided purely by way of non-limiting example, in which:

- the figure. 1 represents a system for distributing signals of the type described in the Italian patent application T098000048.

- the figure. 2 represents the basic system diagram for condominium and / or community distribution of a plurality of digital signals according to the invention.

- the figures. 3 and 4 represent particular embodiments of the invention.

- Figure 5 represents a detail of the invention.

Figure 1 schematically describes the solution proposed in the aforementioned Italian patent application TQ98A000048.

The digital modulated QPSK (Quadrature Phase Shift Keying) signals coming from satellite are received through an antenna 4, to be then converted into a first intermediate frequency (0.950-2.150 GHz) in a well-known LNB (Low Noise Block) represented by block 5 , the signals are then preselected by block 12, which is a transponder preselector circuit, as a function of the polarization (horizontal or vertical) and of the band (high or low).

The signals are then sent to a QPSK / QAM transmodulator, represented by block 13, which selects the chosen QPSK digit signal, demodulates it, remodels it in QAM, and converts it into a predetermined personal channel for the exclusive use of the single user. The signal is then sent to a mixer 3.

The COFDM (Coded Orthogonal Frequency Division Multiplexing) modulated digital terrestrial television signals are instead received by an antenna 19 and then sent to a COFDM / QAM transmodulator, represented by block 11, which selects a COFDM modulated television signal, demodulates it, remodulates it in QAM, it converts it into the aforementioned personal channel and sends it to mixer 3.

The digital signals CATV (CAble TV) modulated QAM (Quadrature Amplitude Modulai ion) arrive, through a coaxial cable 14 ', to a transmoduiator 14, which selects the digital CATV signal, demodulates it, remodels it in QAM, and converts it into the aforementioned channel staff and send it to the mixer 3.

The mixer 3 also receives, by means of channel amplifiers represented by block 2, also the analog television signals received by an antenna I.

From the mixer 3, the various signals are then distributed, by means of a coaxial cable 8, to the individual users; for this purpose, 9 indicates the signal sockets for user equipment.

In series with the distribution cable 8 at the entrance of each apartment or building there is a stopper-band filter S, represented by blocks 15, i.e. a filter that blocks the passage of signals included in a certain band, i.e. the one reserved for the distribution of digital signals, preventing them from being received inside the apartment or building. This band therefore becomes a reserved band within the condominium and / or community distribution, and is forbidden to all users who do not wish to receive new signals.

Block 16 represents a channel-pass selective filter which, placed in parallel with the tow-band filter S (block 15), allows the single user to receive his own personal channel, which would otherwise be blocked by the tow-band filter 15. The block indicated with the symbol «+» represents an adder of signals. To avoid possible interference, it is advisable that a stopping-band filter 15 is also inserted at the output of block 2. Preferably the aforementioned personal channel has a bandwidth of 8 MHz and is contained in a frequency band between 47 and 862 MHz, preferably between 230 and 445 MHz.

Basically, each user owns one or more transmodulators whose output is contained in a fixed channel of his personal use.

Block 17 represents the interface between the distribution system and the user, ie a device that is used by the user himself to select the transmission source and the desired channel. This occurs by sending to the selection blocks, through the common coaxial cable, a modulated signal such as FSK or PSK allocated in a channel, known as the return channel, with a bandwidth of 50-100 KHz. The return channel is not shown in Figure 1 for simplicity.

Block 18 indicates an IRD (Integrated Receiver Decoder) receiver, which demodulates the digital signal in QAM, decodes it, and sends it, for example to a television receiver, not shown in Figure 1.

Figure 2 shows the diagram of a condominium and / or community distribution system of a plurality of television signals and / or audio signals and / or digital audio and / or video and / or data signals according to the invention. In the figure, the blocks relating to both analogue and digital terrestrial television signals have been omitted as they are not affected by the invention; moreover, the remaining blocks of figure 2 have, with the same reference number, the same function as those already indicated in figure 1. Compared to figure 1, in figure 2 there are five new blocks indicated respectively with 20, 21, 22, 23 and 24, which will now be described in detail.

Block 20 represents a terminal, used by the user both to transmit signals of the upstream type US and to receive signals of the downstream type DS, and is directly connected to the interface 17 already described with reference to Figure 1. Said terminal 20 contains the following well-known functions:

- personal computer function for processing the upstream signals US to be transmitted and the downstream DS signals received;

- encoder function for encoding the upstream signals US to be transmitted;

- QAM modulator function to modulate the US upstream signals to be transmitted; - SCPC-type QAM tuner function for the reception of DS downstream signals;

- QAM demodulator function to demodulate the DS downstream signals;

- decoder function to decode the received downstream DS signals.

The incoming DS downstream signals and the US upstream signals transmitted by block 20 are allocated in the aforementioned personal channel for the exclusive use of the user as will be illustrated below.

The condominium and / or community distribution system of a plurality of digital signals uses the satellite to send the return signals to the provider. The upstream signal US is therefore sent by block 20, through the interface 17, the filter 16, the cable 8 and the mixer 3, to a transmodulator SCPC indicated with the block 21. The latter which demodulates said upstream signal US according to the QAM coding, 10 remodulates according to QPSK coding according to the SCPC mode, then converts said US upstream signal into a frequency compatible with those present within a satellite channel, and finally sends it to antenna 4 for transmission to satellite II DS downstream signal arriving at antenna 4 is sent to a transmodulator 22 which, in addition to the functions of block 13 of figure 1, also acts as a tuner for the QPSK modulated multimedia signals according to the SCPC mode received by a channel satellite; therefore the downstream signal DS arriving at block 22, upon receipt of an appropriate command sent by block 20, is demodulated QPSK with SCPC mode, remodulated with QAM coding and converted into a frequency band contained in the aforementioned personal channel. Through the mixer 3, the cable 8, the filter 16 and the interface 17 the downstream signal DS then reaches block 20.

If the system for the condominium and / or community distribution of a plurality of digital signals uses cable transmission, the US upstream signal is sent from block 20, through blocks 17, 16 and 8, to! mixer 3, and therefore to an SCPC transmodulator indicated with block 23. There the upstream signal US is converted into a frequency band compatible with those associated with a cable channel; subsequently the US upstream signal is sent to the Service provider through 11 coaxial cable 14 '. The downstream signal DS is instead selected by the transmodulator 24, which, in addition to the functions performed by! block 14 already described, tunes the downstream signal DS modulated QAM with SCPC mode and converts it into a frequency band corresponding to the band of the aforesaid personal channel. The downstream signal DS then arrives at block 20 through blocks 3, 8, 16 and 17.

Advantageously, the blocks 21 and 22 can be contained in a single apparatus 25, and the same applies to the blocks 23 and 24 which can be contained in an apparatus 26, as shown in figure 3. Even more advantageously, the blocks 21,22,23 , 24, can be contained in a single apparatus 27, as indicated in Figure 4.

The allocation of the US upstream and DS downstream signals in the personal channel is shown in Figure 5. where the frequency band of the personal channel is indicated with the dotted line YES, normally 8 MHz wide; the continuous line S2 represents the band occupied by the downstream signal DS to which a carrier fi is associated, while the line S3 represents the band of the upstream signal US to which a carrier fi is associated.

Figure 5 also shows some possible frequency allocations of the modulated return channel FSK or PSK, used, as previously mentioned, to control the blocks of the distribution system through the interface 17. In particular, the aforementioned return channel can be positioned in a zone not occupied by the upstream signals US and downstream DS as indicated by the reference number S5, or in a zone in which the frequency response of the personal channel is progressively reduced to zero, i.e. in a so-called roll-off zone, such as indicated by the reference number S4.

If the upstream US and downstream DS signals are simultaneously present in the personal channel, that is, when regretted it works with frequency multiplexing (FDMA mode, i.e. Frequency Division Multiplexing Access); the bands S2 and S3 obviously must not overlap. If, on the other hand, the upstream US and downstream DS signals are present at different times in the aforementioned personal channel, there is operation in time multiplexing (TDMA mode, i.e. Time Division Multiplexing Access).

Of course when the personal channel is used to receive television and / or digital signals. audio and / or data signals, the user through the interface 17 and the return channel deactivates blocks 20, 21, and 23, and switches blocks 22 and 24 to the functions already described respectively for blocks 13 and 14. Operations equivalents are made with respect to the apparatus 25 and 26 of figure 3, or to the apparatus 27 of figure 4. The advantages of the proposed system are clear at this point: in practice, by using the personal channel, a condominium user can use the signals multimedia by installing one or more modules that become his exclusive use and are added to the system without modifying the existing distribution, or by replacing existing modules owned by him, if the user already receives television signals and / or digital audio signals from satellite and cable. This can be done for both downstream signals and upstream channels.

It is clear that numerous variations can be made to the plant object of the present invention, without thereby departing from the novelty principles inherent in the inventive idea.

For example, instead of using the cable or satellite for both upstream and downstream signals as described above, one can send the upstream channel via cable, and receive the downstream signal from satellite, or vice versa. Or the upstream channel, which, as mentioned, is usually transmitted at a low bit rate, can be sent by telephone via a modem connected to block 20, according to known techniques.

Finally, the SCPC transmodulators can comprise a device for storing data in transit, commonly known as a buffer, in which the incoming upstream signals are stored; the signals are sent when said buffer is substantially entirely occupied by the signals. In this case, the upstream signals can come from several personal channels, when for example a group of users agrees to use a single SCPC transmodulator to send the signals, for example via satellite.

Claims (23)

CLAIMS 1. System for condominium and / or community distribution of a plurality of television signals and / or audio signals and / or digital audio and / or video signals and / or data transmitted with different standards, these signals being defined as downstream signals (DS ), comprising means (1, 4, 14, 19) for receiving said downstream signals (DS), where one or more digital signals can be received by a single user of the system by means of a frequency conversion in a predetermined accessible channel only to the aforementioned user, the digital signal present in the aforementioned channel being selectable by the aforementioned user through control means (11, 17, 18, 20) which send a command signal to selection and treatment means (12, 13, 14, 20 , 22, 24), characterized by the fact that the control means (11, 17, 18, 20) are also able to generate one or more digital signals in transmission or upstream signals (US) and convert them into a frequency in the predetermined access channel. ile only to the aforementioned user and second means (21, 23) for selecting and processing said digital signals in transmission, and means (4, 14 ') for transmitting said upstream signals (US) over the air and / or from satellite and / or cable. 2. System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that the selection and treatment means (22, 24) and the second selection and treatment means (21,23) operate on downstream (DS) signals or QAM modulated upstream (US) signals with SCPC mode. 3 System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that said predetermined channel accessible only to the aforementioned user is used in FDMA mode, i.e. the upstream signals (US) and the downstream signals (DS ) are present at the same time in said predetermined channel accessible only to the aforementioned user. 4. System for condominium and / or community distribution of a plurality of signals according to claim 3, characterized in that in said predetermined channel accessible only to the aforementioned user, the upstream signals (US) and the downstream signals (DS) occupy frequency bands not overlapping. 5. System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that the aforementioned predetermined channel accessible only to the aforementioned user is used in TDMA mode, i.e. the upstream (US) and downstream signals (DS) are not present at the same time in the predetermined channel accessible only to the user. 6. System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized by the fact that said predetermined channel accessible only to the user has a bandwidth of 8 MHz. 7. System for the condominium and / or community distribution of a plurality of signals according to claim 1, characterized by the fact that only the upstream signals (US) are transported in said predetermined channel accessible only to the user. 8. System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized by the fact that only downstream signals (DS) are transported in said predetermined channel accessible only to the user. 9. Plant for condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that the upstream (US) signals are sent via satellite and the downstream (DS) signals are received via satellite. 10. Plant for the condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that the upstream (US) signals are sent via cable and the downstream (DS) signals are received via cable. 11. System for condominium and / or community distribution of a plurality of signals according to claim I, characterized by! the fact that the upstream (US) signals are sent via satellite and the downstream (DS) signals are received via cable. 12. System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that the upstream (US) signals are sent via cable and the downstream (DS) signals are received via satellite. 13. System for condominium and / or community distribution of a plurality of signals according to claim 1, characterized in that the return channel is allocated in the aforementioned predetermined channel accessible only to the user in a frequency band (S4, S5) not occupied by the frequency bands (S2, S3) relating to the upstream (US) and downstream signals 14. System for condominium and / or community distribution of a plurality of signals according to claim 13, characterized in that said unoccupied frequency band (S5) is located in an area in which the frequency response of the predetermined channel is accessible only the user is progressively reduced to zero (roll-off zone). 15. System for condominium and / or community distribution of a plurality of signals according to claim 1 characterized in that it comprises means (4) for receiving downstream (DS) signals from satellite, means (5) for amplification and conversion in frequency of said downstream signals (DS), means (12) for selecting said downstream signals (DS), means 14 'for receiving signals via cable, means (3) for mixing said downstream signals (DS) coming from satellite with said downstream signals (DS) coming from the cable, band-stop filter means (15) to prevent the passage of signals contained in a certain frequency band (SI), band-pass filter means (16) to allow the passage of signals contained in the aforementioned frequency band (SI), means (8) for distributing signals, means (17) to which are associated means for remote control (11) and means for receiving and decoding (18), at least one transmodulator for the se downstream signals (22,24), at least one transmodulator suitable for SCPC mode for upstream signals (21,23) and at least one terminal (20) to which at least the following functions are associated: - personal computer to process the multimedia signals to be transmitted and those received - encoder to encode the upstream (US) signals to be transmitted - QAM modulator to modulate the upstream (US) signals to be transmitted. - SCPC type QAM tuner for the reception of downstream (DS) signals. - QAM demodulator to demodulate downstream signals (DS) - decoder to decode the received downstream (DS) signals. 16. System for the condominium and / or community distribution of a plurality of signals according to claim 15, characterized in that the transmodulator (22) and the transmodulator SCPC (21) are contained in a single apparatus (25). 17. System for condominium and / or community distribution of a plurality of signals according to claim 15, characterized in that the transmodulator (24) and the transmodulator SCPC (23) are contained in a single apparatus (26) 18. Plant for the condominium and / or community distribution of a plurality of signals according to claim 15, characterized in that the transmodulators (22,24) and the transmodulators SCPC (21,23) are contained in a single apparatus (27). 19. System for the condominium and / or community distribution of a plurality of signals according to claim 1 characterized in that said second selection and treatment means (21, 23) contains a device for storing the upstream signals (US) in I arrive. 20. System for condominium and / or community distribution of a plurality of signals according to claim 19, characterized by the fact that the incoming upstream (US) signals come from one or more predetermined channels accessible only to the user. 21. System for condominium and / or community distribution of a plurality of signals according to claim 19, characterized in that the upstream signals (US) are sent via cable and / or via satellite when said device for storing the upstream signals (US) arriving or is substantially all occupied by said upstream (US) signals. 22. System for transporting multimedia signals in a signal distribution system in a condominium and / or community, characterized by the fact that a predetermined channel is used for said transport, exclusively used by a single user, through which the user itself receives digital television signals and / or audio signals and / or data and / or data accessible only to the aforementioned user. 23. System for the condominium and / or community distribution of a plurality of signals in a signal distribution system in the condominium and / or community area as it results from the teachings contained in the description and annexed drawings.