WO1999062258A1

WO1999062258A1 - Broad-band signal distribution system for buildings

Info

Publication number: WO1999062258A1
Application number: PCT/IT1998/000272
Authority: WO
Inventors: Alfio Turrisi
Original assignee: Itel S.P.A.
Priority date: 1998-05-25
Filing date: 1998-10-12
Publication date: 1999-12-02
Also published as: IT1299476B1; ITRM980333A1; AU9643898A; ITRM980333A0

Abstract

A composite broad-band signal distribution system for buildings comprises a mixing and filtering unit (7), having as an input via-antenna earth and/or satellite signals and multimedia cable and/or radio signals, and as an ouput a composite broad-band signal, a first portion of the band being reserved for via-antenna earth and/or satellite signals, and a second portion of the band being used for mulitmedia cable and/or radio signals.

Description

"BROAD-BAND SIGNAL DISTRIBUTION SYSTEM FOR BUILDINGS"

DESCRIPTION The present invention relates to a broad-band signal distribution system for buildings.

Two types of television earth and/or satellite signal broadcasting equipments are currently used in buildings, e.g. apartment buildings:

1) Centralized shared-antenna equipment, wherein coaxial wiring consists of a main building down-lead

(backbone) and of horizontal branches obtained by means of passive elements (shunts) installed at every floor; and

2) Single-user customized antenna equipment, wherein to each apartment unit one antenna and one single downlead connection correspond, the latter being a coaxial cable going down from the- building roof to the apartment.

In addition to earth and/or satellite television signals transmitted via antenna, cable or radio broad- band interactive multimedia services have lately proved to be an expanding sector. The SOCRATE project (Coaxial Optical Development by Italian Telecom) , for example, is up to now, Italy' s biggest investment in the field of broad-band cable networks. Other multimedia services are currently being developed in Italy by providers such as Albaco , Infostrada, Stream and Wind.

Obviously, those services— ave -to be offered for

Their use in buildings. In this case, traditional installation techniques involve an additional coaxial wiring of the building. High costs are the main problem with such techniques. Even in cases when distribution equipments are centralized and not customized, costs are elevated,_ due^{^} substantially to the construction of infrastructures for housing the cables feeding the multimedia signals.

The present invention overcomes such prior art 99/62258

- 2 - problems by providing a system which makes integration of cable multimedia services, such as those covered by the SOCRATE project, and traditional antenna ^"equipments for reception of earth and/or satellite television signals possible by using existing television equipments and infrastructures therefor.

A composite broad-band signal distribution system for buildings is therefore provided, a first portion of said band being used for earth and/or satellite signals received via antenna, and a second portion of said band being used for multimedia signals received via cable and/or radio, the system comprising a . filtering and mixing unit, having as an input said earth and/or satellite signals received via antenna and said multimedia signals received via cable and/or radio, and having as an output said composite broad-band signal.

In this way, construction works inside buildings and single apartments are no longer needed, with a remarkable reduction of the costs associated with the wiring of the building for distribution of said broad-band services.

Both kinds of buildings mentioned above, i.e. provided either with centralized or customized equipments, have in common the presence of an already existing infrastructure. Whether the quality of the antenna coaxial network system is good enough to meet multimedia signal cable transmission requirements or a replacement is neces-sary because of- its - inadequateness, installation work and costs associated thereto

(replacement of passive components such as shunts^", floor branching devices, sockets etc.) would be reduced to a simple cable replacement, excluding any need for new brickworks .

Furthermore, ^" the present invention solves a problem which at first sight would make integration _of via- antenna earth and satellite services and multimedia cable services unadvisable. 99/62258

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In fact, receiving apparatuses for via-antenna broadcasting are designed in order to allow distribution to users of television signals in the band fcretween 52 and

862 MHz (VHF and UHF bands between BI and BV) . Such band is coincident with the previous band allocation for the

SOCRATE project, comprising both diffusive analog signals

(52-470 MHz) and digital signals (470-860 MHz) . The new perspectives for broad-band networks provide only the distribution of multimedia services, whose band generally ranges between 470_ and 860 MHz (UHF bands BIV and BV) .

Moreover, it should be noted that multimedia signals involve the use of an up-stream band ranging between 5 and 40 MHz, allowing interaction between users and providers of the programs transmitted through via cable multimedia signals.

The present invention solves the above-mentioned problem by shifting the frequency spectrum usually occupied by via-cable transmitted multimedia signals.

A further advantage of the present invention is that in a preferred embodiment the filtering and mixing unit allows the use of a single earth antenna (UHF, VHF) and of a single satellite antenna for the whole building, completely eliminating the need for the exceedingly big number of antennas now installed on most buildings. The present invention will be hereinafter disclosed by preferred embodiments thereof, shown as a non-limiting example. Reference will be made to figures in the annexed drawings, wherein: figure 1 shows a diagram of the frequency band allocation for the signals integrated by the present invention; figure 2 shows a block diagram of the system according to the present invention; figure 3 shows a detailed diagram of the unit 7 of figure 2; figures 4 and 5 show two embodiments of the conversion unit 6 of figure 2; figures 6, 7 and 8 show two embodiments of the user interface 17 of figure 2-; figure 9 shows an alternative embodiment for the units 6 and 7 of figure 2; figure 10 shows an embodiment of the present invention with access of via cable multimedia signals from the bottom upwards; figure 11A shows an embodiment of the present invention in case of single-user shared-antenna equipment with a single satellite switchboard; figure 11B shows an embodiment of the present invention in case of single-user customized antenna equipment; and figure 11C shows an embodiment of the present invention in case of single-user shared-antenna equipment with a customized satellite switchboard.

Figure 1 shows a diagram with frequency band allocations for the different signals integrated by the present invention, hereinafter indicated by letters a) b) and c) , so as to generate a composite Horoad-band signal: a) Earth broadcasting analog television signals

Band allocation for said signals is indicated in the figure by squared-in rectangles 1. As for signals that are normally allocated to band Bill (VHF) between 174 and 230 MHz (for example, RAI 1) , they are shifted and transmitted in band BT, between 47 -ad 70 MHz, in order to leave band Bill free for via-cable multimedia signals.

As for signals in- bands BIV and BV (UHF) , between 470 and 860 MHz, no shifting is provided. Considering that such signals occupy an 8 MHz band, the reception of

49 channels for an equal number of programs will be possible . b) Satellite analog and digital television signals Band allocation for such signals is indicated in the figure by a rectangle with diagonal lines 2. Digital signals occupy a band of^" 27÷39 MHz per channel, with 6-8 programs per channel. Analog signals occupy a band having the same width but with one program per channel. Both these types of satellite signals have been allocated in the band ranging from 950 to 2150 MHz. Alternative embodiments can involve the extension of said band up to 2400 or 3000 MHz.

If necessary, satellite analog television signals can be allocated to frequency values within Low and High S-band (230÷470 MHz), Bill, BIV and BV (470-860 MHz), in cases when allocation within such bands does not involve earth channels. Such property is illustrated by a dotted circle A of figure 1. c) Via-cable digital and/or analog multimedia signals (hereinafter shortly defined as multimedia signals)

Band allocation -for such signals is indicated in the figure by a black rectangle 3. Such signals occupy a 7/8 MHz band per channel, with 6-8 programs per channel. The present invention provides their distribution in the band ranging between 70 and 460 MHz, or in a portion thereof. In a preferred embodiment of the present invention, the band between 88 and 108 MHz ^"is kept free in order to avoid interference with FM radio broadcasting. Such property is illustrated by a dotted circle B of figure 1, wherein radio signal band allocation is indicated by a spotted rectangle 4.

The band between 70 and 460 MHz caft- moreover contain, as an. alternative to cable television channels, digital satellite channels or multimedia services from different sources, e.g. telephone-related services, according, for example, to the representation in the dotted circle C of figure 1.

Moreover, an up-stream band between _5 and 40 MHz has been advantageously provided, as already set forth above. In order to guarantee that the existing cables are able^" to meet satellite service requirements, the system according to the present invention advantageously provides an equalized amplifier unit, hereinafter defined as satellite adapter switchboard. Such satellite adapter switchboard allows signal equalization and amplification which varies in accordance with the frequency allocation of the signals.

The subsequent figure 2 shows a block diagram of the system according to the present invention when installed in a building equipped with a centralized shared-antenna. Multimedia cable or radio signals are fed along a bi-directional connection 5, for example by way of a HFC connection, i.e. an optical fiber/coaxial cable hybrid.

A conversion unit 6 allows possible frequency shifting of such multimedia signal. Typical cases provided by the present invention are shifting from the 4^70/860 MHz band to the 70/460 MHz band, or shifting from the 500/660 MHz band to the 30/460 MHz band. More -still, shifting of the multimedia signal band may sometimes even prove unnecessary. Such is the case ^"when there is no conflict -between the frequency band occupied by cable multimedia signals and the frequency band occupied by antenna signals. Preferred embodiments of said conversion unit 6 will be illustrated in detail in the successive figures 4 and 5.

A mixing and filtering unit 7 mixes earth, satellite and cable .signals. In particular, earth signals coming from VHF and UHF antennas- are connected to unit 7 by means of the ^" uni-directional connections 8 and 9; satellite signals transmitted by the SAT antenna are connected to the unit 7 by means of the uni-directional connection 10; and multimedia signals coming from the conversion unit 6 are connected to the mixing and filtering unit 7 by means of the bi-directional connection 11.

Via-antenna earth signals coming along the connection 8 are frequency-shifted, by unit 7, to band BI when they occupy band Bill or, in case they do not occupy band Bill, they are transmitted without variations in their frequency band. Via-antenna earth signals coming along the connection 9 and via-antenna satellite signals proceeding along the connection 10 are transmitted without variations in their frequency band.

The mixing and filtering unit 7 will be illustrated in greater detail in figure 3.

The broad-band mixed signal outputted from unit 7 is fed along a bi-directional connection 12. The bidirectional connections 11 and 12 are such as to provide the presence of a channel occupying the band between 5 and 40 MHz, in order to allow transit of the up-stream user's channel during the use of the multimedia services. The building terrace and ground-floor location are indicated in the figure by dotted-and-dashed horizontal lines 13 and 14, respectively. Floor shunts and apartment terminals needed to transmit the broad-band signal proceeding along the bidirectional connection 12 to the users in the building are respectively indicated by numerals 15 and 16. Such shunts and terminals distribute signals to apartment units by maintaining the same signal power level for each user. Floor shunts will have a passband between 5 and 40 MHz_ and their number will be equal to the number of floors of the building, with a possible floor-by-floor differential branch attenuation. Feedthrough sockets and/or user terminals are broad-band (0-2400 MHz) total- shielding sockets with a low insertion loss available on the market, for example TV/SAT sockets manufactured by FAIT or TICINO.

The branching device 15, in correspondence of the ground floor is a terminal device, represented in the figure by a connection to ground through a resistor Rl . The system according to the present invention provides that users are equipped with a user interface 17 and a cable-transmitted information decoding unit 18, the latter being connected to the television set 1 by means of a peritelevision socket 20.

Via-antenna earth and satellite signals are transmitted to the antenna socket 21 of the television set 19 directly from the user interface 17, through a connection 22. The cable-transmitted information decoding unit 18 is of a per se known type, usually referred to as Set-Top Box .

The user interface 17 carries out on via cable multimedia signals operations inverse to those carried out by the unit 6 by conversion means contained therein. That means that if the unit 6 has shifted multimedia signals from the 470-860 MHz band to the 70-460 MHz band, the user interface 17 -will carry out a reverse shifting, transmitting the reverse-shifted signal to the cable- transmitted information decoding unit 18, along a bidirectional connection 23, which is separate from the connection 22. Preferred embodiments of said interface 17 will be illustrated in detail in subsequent figures 6,7 and 8. For sake of clarity, the satellite signal decoding unit of a per se known type is not shown in the figure, while its ^"location is to be intended along connection 22, between the user interface 17 and the antenna socket 21.

It is therefore clear from figure 2 that the present invention allows integration between the wiring of the building for multimedia signals and traditional antenna equipment for reception of earth or satellite broadcast television channels. All channels are broadcast only by way of the existing television equipment. Figure. 3 shows a detailed diagram of the mixing and filtering unit 7 of figure 2. Firstly, a converter 24 is provided, which shifts in frequency from band Bill to band BI the television signals transmitted by the VHF antenna. For example, a Telec or Conv/G-type converter can be used. A band-pass filter 25 is also provided, which allows passage of UHF BIV and BV bands only, between 470 and 860 MHz among television signals transmitted by the UHF antenna. Said filter can if necessary be placed inside the subsequent mixing/amplifying device 26, which mixes the signals outputted from the converter 24 and from band-pass filter 25. Therefore, the connection 27 at the output of the mixer 26 feeds a signal occupying bands BI, BIV and BV.

Downstream of mixer 26 or incorporated thereinto, a broad-band amplifier is also provided, not shown in the figure for clearness purposes, for distribution in the building of the signals -mixed as illustrated above. For example, a FAIT C533 or C633 model could be employed.

A first circulator/combiner 28 is also provided to allow, along connection 29, the coupling of the signal proceeding along connection 27, and carrying information transmitted by earth antennas, with the signal coming from the bi-directional connection 11 ^"and carrying multimedia cable information coming from the unit 6. Downstream of the first circulator/combiner 28 and connected thereto by the bi-directional connection 29, a second circulator/combiner 30 is provided to allow, along the bi-directional connection 12, the coupling of the signal coming from the bi-directional connection 29 with the signal coming from the connection 31, and carrying the information coming from the SAT satellite antenna. A satellite adapter switchboard 32, for example a IARE 9740, is preferably provided between the SAT satellite antenna and the circulator 30. Said switchboard advantageously eliminates the need for ^" special wiring for- band L (950-2400 MHz) frequency signals. 99/62258

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As the connections 11, 12 and 29 should allow signal flow in both directions, circulators/combiners 28 and 30 will be designed to avoid passage of ^"the up-stream flow from the bottom upwards along connections 27 and 31. Such circulators/combiners could be, for example, assembled from P2 FAIT and MDS FAIT products, or similar products manufactured by RAYCHEM or RADIOSHACK.

Reference will be now made to figure 4, showing a detailed diagram of the unit 6 of figure 2. Firstly, a first circulator 33 is provided to feed, along the uni-directional connection 34, the multimedia signal coming from the bi-directional connection 5 from the multimedia service provider. The signal is then mixed in a ixer 35 with a signal having a predetermined frequency, generated by a local oscillator 36. Fosc frequency of the embodiment of the figure will be 930 MHz.

The signal, mixed ars explained above, is then filtered by a band-pass filter 37, to obtain, along the connection 38, a signal occupying a 70-460 MHz frequency band. Such signal will pass through a second circulator 39, to allow feeding thereof along the connection 11, and from there to the mixing unit 7.

As for the up-stream flow coming from the connection 11 in the opposite direction with respect to the one considered up to now, the circulator 39 will direct it along the connection 40 and the band-pass filter 41, in order to obtain passage, along the connection 42, of a signal occupying a frequency band between 5 and 40 MHz. Such signal will then be fed, by means of the circulator 33, along the bi-directional connection 5 and from there directed to the multimedia service provider.

Figure 4 is purely an ideal diagram. For example, one or more signal amplifiers or injection filters disposed among the different components illustrated can be provided. Moreover, shifting to different bands by simply varying oscillation frequency of the oscillator 36 and passband of the band-pass filter 37 is also possible. For example, the multimedia signal fed along the bi- directional connection 5 can be expected to occupy a 500- 660 MHz band. In this case, Fosc oscillation frequency of the local oscillator 36 will be 200 MHz, while band-pass filter 37 passband will range ^"between 300 and 460 MHz.

On the contrary, when conversion of multimedia signal fed along the bi-directional connection 5 is not needed, neither mixer 35 nor local oscillator 36 nor band-pass filter 37 need to be provided.

If needed, both local oscillator 36 and .band-pass filter 37 can be adjustable, in order to fulfil different installation requirements.

Figure 5 illustrates a further embodiment of the unit 6, wherein double conversion of the signal occurs between input and output of the unit 6, by means of two local oscillators and two band-pass filters. In particular, this alternative embodiment takes into account the fact that the use of a single -local oscillator can generate spurious frequencies as they would fall within the range of the frequencies . to be shifted, therefore causing signal distortion. Thus figure 5, which provides the feeding of a signal occupying the 470-860 MHz band along the connection 5, shows a first local oscillator 43 with an oscillation frequency of 2360 MHz, a first mixer 44 and a first band-pass filter 45 with a passband ranging between 1500 and 1890 MHz, then a second local oscillator 46 with an oscillation frequency of 1960 MHz, a second mixer 47 and a second band-pass filter 48 with a passband ranging between 70 and 460 MHz.

Referring now to figure 6, a detailed diagram of the user interface 17 is shown, corresponding to the embodiment illustrated in the preceding figure 4. Firstly, a circulator 49 is provided, to feed the broad-band signal coming from the bi-directional connection 53 from the apartment terminal 16 both to a band-pass filter 50 and to a connection 22, respectively, by means of a splitter 52.

The band-pass filter 50 feeds, along a connection 54, signals with a frequency band ranging between 70 and 460 MHz. Such signals are mixed inside a mixer 55 with a predetermined frequency generated by a local oscillator 56. Fosc frequency of the embodiment of the figure will be 930 MHz. The so mixed signal is filtered by a bandpass filter 57, in order to obtain, along a connection 58, passage of a signal which occupies a 470-860 MHz frequency band. Such signal is then passed through a circulator 59 in order to allow its being fed along the connection 23, therefrom proceeding to a decoding block 18.

As for the up-stream flow coming from the connection 23 in the opposite direction with respect to the one considered up to now, the circulator 59 will feed it along the connection 60 and the band-pass filter 61, in order to obtain, along the connection 62, passage of a signal occupying a 5-40 MHz frequency band. Said signal will then be fed, by means of the circulator 49, along the bi-directional connection 53 and from there to the multimedia service provider.

Downstream of_ the splitter 52, along the connection 22, via-antenna earth and/or satellite signals are fed to the antenna socket 21. Figure 6 is an ideal diagram. For example, one or more signal amplifiers or injection filters, disposed between the different components previously illustrated, can be provided.

When conversion of the multimedia signal is not needed, neither the local oscillator 56 nor the band-pass filter 57 need to be provided. On the contrary, when the multimedia signal occupies a 500-660 MHz frequency band, changes like the ones illustrated for unit 6 will be made. Therefore-, oscillation frequency of the local oscillator 56 will be 200 MHz, while passband of the band-pass filters 50 and 57 will be 300-460 MHz and 500-660 MHz respectively.

With reference to this, last embodiment, figure 7 snows a variation thereof without a local oscillator, with the further advantage of having a user apparatus providing only passive elements, which does not need to be powered. Referring to said figure, the signal fed along the connection 63 is directed, by means of a splitter 64, along two different paths 65 and 66, placed downstream of which two band-pass filters 67 and 68 are provided respectively to allow passage, along- the respective connections 60 and 70, of the signals having a 200 MHz frequency and of the signals having a frequency ranging from 300 and 460 MHz. Such signals are mixed inside a mixer 71, then passed through a band-pass filter 72 to allow the feeding to the block 18 of multimedia signals occupying a 500-660 MHz.

Via-antenna earth and satellite signals are fed to antenna socket 21 along connection 22, downstream of the splitter 52. In both embodiments of figure 6 and 7, it will be possible to provide that both local oscillators and bandpass filters are adjustable, to fulfil different installation requirements.

Referring now to figure 8, an alternative embodiment of the user interface 17 is shown, corresponding to the embodiment of unit 6 shown in the preceding figure 5. Figure 8 which provides the feeding of a signal occupying a 70-460 MHz band along the connection 53 and the bandpass filter 50, shows a first local oscillator 73 having a 1960 MHz oscillation frequency, a first mixer 74, and a first band-pass filter 75, with a passband ranging between 1550 and 1890 MHz and then a second local oscillator 76 having an oscillation frequency of 2360 MHz, a second mixer 77 and a second band-pass filter 78^' whose band ranges between 470 and 860 MHz. A further embodiment of the user interface 17 provides broad-band remote controlled and possibly modulating .tuning devices. By means of a remote control, users can modify the tuner's local oscillator frequency and select one channel among those available in the band, e.g. between 70 and 460 MHz. Said channel is first of all brought to a fixed frequency (usually 38.9 MHz), then converted into the desired UHF frequency (channels from 21 to 60) . The output signal is then inputted to the decoder 18, which can be made in a simplified version, as a tuning portion is no longer -needed. This solution results in a better reception, as broad-band conversions provided by the previous embodiments are avoided.

An alternative embodiment to those illustrated in figures 2, 6, 7 and 8 can provide the feeding of the earth and/or satellite signals received by the antenna to the antenna socket 21 to occur upstream of the- user interface 17, e.g. having the splitter 52 placed inside the apartment terminal 16 instead of inside the user interface 17. Therefore, according to this embodiment, the connection 22 would be carried out starting from the apartment terminal 16, or could even correspond to the existing equipment.

Said embodiment turns out to be particularly useful in case users do not want to receive- multimedia signals, therefore not needing the user interface 17.

Figure 9 shows an alternative embodiment of the blocks 6 and 7. This embodiment provides for the band BI VHF signal to be first of -all mixed with the multimedia cable signal . The signal outputted from^" the BIII/BI converter 24 is fed to a circulator/combiner 79 located inside the unit 6 between the band-pass filter 37 and the circulator 39. A signal containing both information related to the multimedia signal and to the BI band earth signal will pass along the uni-directional connection 80. Said signal will then be fed along the bidirectional connections 11, 29 and 12 by means of the circulators 39, 28 and 30.

Figure 10 shows an embodiment of the present invention wherein the access of cable multimedia signals (e.g. HFC network) to the building occurs upwardly, rather than downwardly. In this case, the conversion unit 6 is located on the ground floor, not on the terrace. The only real difference with respect to the embodiment illustrated in figure 2 is that the branching device 15 is a feedthrough rather than a terminal branching device. Furthermore, a circulator/isolator 105, having one input connected to the ground through a resistor R2, will have to be provided, placed along the bi-directional connection 12 between the mixing device 7 and the first of the branching devices 15.

In a further embodiment of the system according to the present invention, the bi-directional connection between the service provider and the building, i.e. between the multimedia signal conversion unit 6 and the multimedia services provider, occurs via radio. In particular, the conversion unit 6 will comprise a reception sub-block for frequency-shifting, e.g. to the 70-460 MHz band, the- signals received via radio (IF-RX, intermediate receiving frequency) , and a transmission sub-block for frequency-shifting the signals to be transmitted to the service provider from the 5-40 MHz band to a predetermined frequency band (IF-TX, intermediate transmitting frequency) .

Reference has been up to now made to a building provided with a centralized shared-antenna equipment. The present invention can however apply to different configurations, for example single-user customized SAT antenna equipment, single-user SAT shared-antenna equipment with a single satellite switchboard and single- user customized SAT antenna equipment with customized satellite switchboards.

Subsequent figures from 11A to 11C will show embodiments of the present invention referring to such configurations. In said figures reference_will be made to two devices typically employed with satellite antennas, i.e. the LNB (Low Noise Block) downconverter and the satellite switchboard. Such devices have not been illustrated in figures from 1 to 10 for clearness purposes, being however part of the system.

In particular, the LNB is a device that can convert the whole frequency range reserved for satellite television broadcasting (low band from 10.7 to 11.7 GHz, high band from 11.7 to 12.75 GHz), in the frequency band ranging between 950 and 2150 MHz. It is known that in order to optimize frequency utilization, satellites can transmit different signals through a single frequency due to their different polarizations. Therefore, each LNB has four possible outputs: low band with vertical polarization, low band with horizontal polarization, high band with vertical polarization, high band with horizontal polarization.

The satellite switchboard's function is that of interfacing the four_ LNB outputs with the building coa-xial cable distribution network.

Figure 11A shows a diagram referring to the embodiment in case of single-user shared-antenna equipment with a single satellite switchboard. A LNB 81 having the above described four outputs 82 as well a satellite switchboard 83 are located downstream of a SAT satellite antenna of the IF/IF conversion type, manufactured for example by IARE or IRCO.

Downstream of the circulator 30, a signal divider 84, e.g. the PS4 manufactured by FAIT, is installed to distribute the broad-band signal coming from the connection 12 to the single-user equipment, four of which are shown in the figure by way of example. In said embodiment, the mixing between via-antenna earth signals, satellite signals, and multimedia cable and/or radio signals occurs upstream of the divider.

Figure 11B shows a diagram referring to single-user customized SAT antenna and SAT switchboard equipment. The example -shows four different SAT satellite antennas. With respect to prior embodiments, satellite signals are not mixed with earth and multimedia signals immediately after the mixing of the latter at the output of circulator 28, but after the output of the composite earth + multimedia signal from a signal divider 85, for example a PS4 manufactured by FAIT.

Therefore, in this embodiment a plurality of circulators 86, four of which are shown in the figure, is provided, to allow, along the connection 87, the mixing of signals coming from the connection 88 (earth + multimedia signal outputted from the divider ^~85) and 89 (satellite signal).

The broad-band signal resulting along the different connections 87 will be thereby distributed to each single apparatus. In this embodiment, the mixing of via-antenna earth signal and multimedia cable and/or radio signals occurs upstream of the divider, while the mixjLrrg with via-antenna satellite signals occurs downstream of the divider . Figure 11C shows a diagram of the embodiment involving a single-user shared-antenna equipment with customized satellite switchboards. For ease of representation, an example having only two satellite switchboards is. illustrated in the figure. In the embodiment shown _ in the figure, the signal outputted from the LNB 81 is fed to a splitter 90, then from there to two satellite switchboards 83, and again from there, by means of satellite adapter switchboards 32 to respective-circulators 91, their number being equal to that of the apparatuses to be fed. Such circulators allow the mixing, along connection 92, of the signals coming from the connections 83 (earth + multimedia signal outputted from divider 94) and 95 (satellite signal).

The broad-band signal obtained along the different connections 92 will be transmitted to each single apparatus. Also in this embodiment the mixing of via- antenna earth signals with multimedia cable and/or radio signals occurs upstream of the divider, while the mixing with via-antenna satellite signals occurs downstream of the divider. The present invention has been up to now described according to preferred embodiments thereof, by way of non-limiting examp^~les . It is to be understood that other possible embodiments are possible falling within the scope of the claims annexed hereinafter. For example, the use in buildings not equipped with satellite antennas and that do not intend to be^" provided with ^" said services however wanting to be connected to services given by telecommunications providers different from those having currently access to users, is also possible.

Claims

1. A composite broad-band signal distribution system for buildings, a first portion of said band being used for earth and/or satellite signals received via antenna, and a second portion of said band being used for multimedia signals received via cable and/or radio, the system comprising a filtering and mixing unit (7), having as an input said earth and/or satellite signals received via antenna and said multimedia signals received via cable and/or radio, and having as an output said composite broad-band signal.

2. The system according to claim 1, characterized in that it further comprises a plurality of user interfaces (17) placed each- one in proximity of the respective user, having as an input (53) said composite broad-band signal and having as an output said multimedia signals.

3. The system according to- claim 2, characterized in that feeding of said earth and/or satellite signals to antenna socket (21) occurs along a further output of said user interfaces (17).

4. The system according to claim 2 or 3, characterized in that it comprises- a conversion unit (6), for frequency-shifting of said multimedia signals, the output of said conversion unit (6) being inputted to the mixing and filtering unit (7), each interface of said plurality of user interfaces -L17J comprising conversion means for restoring the multimedia signals _to the frequencies occupied prior to undergoing frequency shifting by the conversion unit (6) .

5. The system according to any of the claims from 2 to 4, characterized in that each of said user interfaces

(17) is-made of passive elements.

6. The system according to any of the claims from 2 to 4, characterized- in that each of said user interfaces

(17) comprises broad-band remote-controlled tuning devices .

7. The system according to any of the claims from 4 to 6, characterized in that said conversion unit (6) and said conversion means are frequency-adjustable.

8. The system according to any of the preceding claims, characterized in that the second portion of the band of the composite signal comprises an up-stream sub- portion to allow the interaction between users and providers of^" programs broadcast by the multimedia signals.

9. The system according to any of the preceding claims, characterized in that the access to users of the multimedia signals occurs downwardly.

10. The system according to any of the claims-from 1 to 8, characterized in that the access to users of the multimedia signals occurs upwardly.

11. The system according to any of the preceding claims, characterized in -that the filtering and mixing unit (7) comprises means for shifting, from band BI to band Bill, the earth signals received via antenna.

12. The system according to any of the preceding claims, characterized in that the filtering and mixing unit (7) comprises a satellite adapter switchboard (32) .

13. The system according to any of the claims from 2 to 12, characterized in that the frequency conversion unit (6) and the user interface (17) conversion means carry out a double conversion-- to eliminate spurious frequencies generating signal distortion.

14. The .system according to any of the preceding claims, characterized in that it comprises at least one single-input multiple-output signal divider (84;85;94) to allow the use of said system in buildings without a centralized equipment.

15. The system according to claim 14, characterized in that -said divider (84) is provided in buildings with a single satellite antenna and a single satellite switchboard, wherein the mixing of via-antenna earth signals, via antenna satellite signals, and multimedia signals occurs upstream of said divider.

16. The system according to claim 14, characterized in that said divider (94) is provided in buildings with a single satellite antenna and customized satellite switchboards, wherein the mixing of via-antenna earth signals .with multimedia signals occurs upstream of said divider, while the mixing with satellite signals occurs downstream thereof.

17. The system according to claim 14, characterized in that said divider (85) is provided in customized satellite antenna building equipment, wherein the mixing of via-antenna earth signals with multimedia signals occurs upstream of said divider, while the mixing with satellite signals- occurs downstream thereof.