[0001] The present invention relates to a broadband service distribution method.
[0002] Modern telecommunications systems currently carry, in addition to ordinary voice
calls, other services for users, including the transmission of television pictures
and programming, such as cable television and data transmission services such as the
well-known Internet.
[0003] The passband per user required to carry these services is far greater than the band
required to carry ordinary telephony.
[0004] Accordingly, telecommunications companies are developing and installing so-called
"broadband access networks".
[0005] These specialized networks are designed to carry digital signals to users, characterized
by very wide passbands in the directions from the exchange to the user and with narrow
bands in the opposite direction.
[0006] This is due to the fact that user requests occupy a small amount of band in comparison
with the large amount of information downloaded to the user.
[0007] The broadband access network is usually constituted in a hybrid, i.e. mixed, manner
by a fiber-optic part and by a coaxial-cable part and is accordingly termed "Hybrid
Fiber Coaxial (HFC) network".
[0008] Accordingly, Figure 1 illustrates an exemplifying diagram in which the optical part
is used to carry signals from one location, designated by the reference numeral 1
and termed "head end", where the various programs to be fed into the broadband network
are concentrated, to a point, designated by the reference numeral 2 and termed "fiber
node", of the broadband network implemented with the hybrid fiber coaxial (HFC) network
system, in which the optical signal that arrives from the fiber is converted into
an electrical signal for transmission over coaxial cable.
[0009] The coaxial cables 4 used to distribute the signal to the users branch out from the
fiber node 2, which is located proximate to the users, generally designated by the
reference numeral 3.
[0010] Inside the building, and starting from the so-called "network termination" (NT),
designated by the reference numeral 5, the coaxial cable 4 branches out, by means
of a distribution system designated by the reference numeral 6, towards the individual
users, designated by the reference numerals 7.
[0011] Special equipment is required, however, to receive the services: in the case of digital
cable television, a special receiver is used which is capable of performing the following
operations: tuning to a channel typically in the band between 47 and 862 MHz; decrypting
the signal (in the case of pay channels); decompressing the signal according to the
MPEG2 standard; and sending it to the television set, designated by the reference
numeral 8, in the standard PAL format.
[0012] The above-described distribution system known as Hybrid Fiber Coaxial (HFC) network
is used extensively because it is a solution having a good price/performance ratio.
[0013] This system, however, entails many drawbacks, including mainly the laying of coaxial
cables inside buildings and along city streets.
[0014] Particularly in urban areas and in older buildings, laying said cables entails demolition
and restoration work which is particularly expensive and sometimes altogether unacceptable
for users.
[0015] In Figure 1, the expression "distribution node" references the point of access to
the broadband network for channels arriving from a plurality of head ends and at the
same time the point of distribution of all the transmission channels towards the users.
[0016] As a partial solution to these drawbacks, which are worsened by the extent to which
they force the user of the service to perform unwanted structural work, it is known,
in order to transmit broadband signals efficiently and inexpensively, to use different
systems, including the one known generically by the name "broadband asymmetric transmission
system" or Asymmetric Digital Subscriber Loop (ADSL) or similar systems termed XDSL,
where the letter X must be replaced in each case with the technology being used.
[0017] The expression ADSL designates a broadband transmission system capable of using the
conventional telephone wire pair, designated by the reference numeral 9, to carry
broadband digital channels simultaneously with the ordinary telephone service, also
allowing communication between the user and the head end by means of a return channel
(upstream channel) at low speed (differently from the downstream channel, which operates
at high speed, hence the term "asymmetric").
[0018] The ADSL broadband asymmetric transmission system thus uses the ordinary wire pair,
which currently reaches every home, to carry a broadband channel over said wire pair.
[0019] This ADSL broadband asymmetric transmission system preserves the ordinary service
that can be used with a telephone set, designated by the reference numeral 10, and
allows the user to request the chosen program or service from the service exchange
by means of the upstream channel.
[0020] The exchange 50, however, must be capable of supplying the programs on demand and
individually to each user: this type of service is known as Video On Demand (VOD)
and entails the presence, in the exchange, of power and accordingly expensive equipment
known as "video servers", capable of serving the requests of users, or of equally
expensive switching systems which typically use ATM (Asynchronous Transfer Mode) technology.
[0021] Substantially, the video server is a powerful computer capable of transmitting programs
and services to users at the user's request, while the ATM switch alternatively switches
the requested channel towards the user.
[0022] Accordingly, any use of the ADSL broadband asymmetric transmission system configures
the network as point-to-point, as shown schematically in the accompanying Figure 2,
between the exchange and the user, differently from the above-mentioned distribution
structure known as hybrid fiber coaxial (HFC) network, in which the network gradually
branches out from the exchange or head end to the users.
[0023] The ADSL broadband asymmetric transmission system therefore connects the user to
broadband services only with a channel at a maximum rate of 8 Mbit/s and uses the
existing wire pair, sharing it with the basic telephone services. This structure,
however, entails very expensive equipment and a radical change in distribution concept.
[0024] The aim of the present invention is to solve the described technical problems, eliminating
the drawbacks of the cited prior art and thus by providing a solution which allows
to eliminate the costs and inconveniences of coaxial-cable wiring for the user.
[0025] Within the scope of this aim, an important object of the present invention is to
provide a solution in which the end user does not have to perform any specific work
at the masonry level in his home in order to utilize the broadband service.
[0026] Another important object of the present invention is to provide a solution which
entails low implementation costs for the distribution of the broadband service.
[0027] Another important object of the present invention is to provide a solution which
does not require the use of very expensive equipment such as powerful computers capable
of serving the user's requests.
[0028] This aim, these objects and others which will become apparent hereinafter, are achieved
by a method for distributing broadband services characterized in that it provides
for:
-- separating a broadband front end of a receiver circuit from other portions of the
circuit;
-- placing said front end in utility closets of a building;
-- connecting said front end to a so-called "modulator-demodulator" (ADSL modem) or
to a so-called "modulator" or to an amplifier;
-- transferring a signal from said modulator-demodulator or from said modulator or
from said amplifier and the sign from a telephone exchange to a first adder in order
to mix the broadband and telephone services;
-- transferring signals from said first adder over a telephone wire pair to an individual
end user; and
-- splitting the signals to a telephone and to a television set.
[0029] Further characteristics and advantages of the invention will become apparent from
the following detailed description of a particular embodiment thereof, illustrated
only by way of non-limitative example in the accompanying drawings, wherein:
Figure 1 is a diagram of a prior art arrangement;
Figure 2 is another diagram of another prior art arrangement;
Figure 3 is a block diagram of the structure of a digital receiver;
Figure 4 is a schematic view of the device according to the present solution;
Figure 5 is a block diagram of an indication of a possible mode of operation;
Figure 6 is a schematic view of the device according to the present invention, using
the modulator in the utility closet of the house;
Figure 7 is a schematic view of the device according to the present invention, without
using the modulator;
Figure 8 is a block diagram of an indication of a possible operation with a modulator,
as shown in the diagram of Figure 6;
Figure 9 is a block diagram of an indication of a possible operation without a modulator,
as shown in the diagram of Figure 7.
[0030] The structure of a digital receiver (see Figure 3), generally designated by the reference
numeral 11, for broadband services is described with reference to the above figures,
and particularly with reference to Figure 3, in order to improve the comprehension
of the method according to the invention. The receiver comprises a block, designated
by the reference numeral 12, which is termed "front end" and is constituted by an
electronic module which collects the signals 4 arriving from the network and processes
them appropriately by tuning and conditioning them so that they become usable by the
subsequent stages of the receiver.
[0031] Substantially, the front end 12 has the purpose of selecting the selected channel
within the band available to the user: the front end 12 also converts the received
signal 4 into a plurality of data which are then processed by the other subsequent
stages.
[0032] The reference numeral 13 designates a block, termed "conditional access", which is
a system that allows access to services, for example the viewing of a television channel,
only to authorized users (for example to those who pay a subscription), preventing
use by unauthorized users by means of transmission encryption methods.
[0033] The reference numeral 14 designates a block conventionally termed "Mpeg demux", which
is constituted by a system for the digital encoding and compression of video signals
which, by means of appropriate decoders 15 (video and audio decoders) and digital
to analog converters (DAC) 16, carry the signals to a SCART socket 17, the entire
system being managed by means of a microprocessor 18.
[0034] In the method, the broadband front end 12 of the receiver 11 is separated from the
rest of the circuit, placing it in the fiber node 2, as shown in Figure 4 or in the
same point of the building where the wire pairs of the telephone service enter said
building and therefore typically in the utility closets located in the basement of
the house.
[0035] There, the front end 12 is connected to a coaxial cable 4 of the fiber node 2; in
the prior art, said coaxial cable 4 would have had to reach the user directly.
[0036] The front end 12 is then connected to a modulator-demodulator (ADSL modem), designated
by the reference numeral 19 (see Figure 6), or to a modulator 23 (see Figure 7), which
in turn sends the signal to a first adder 20 which also receives a signal from a telephone
exchange generally designated by the reference numeral 21.
[0037] The front end selects the channel to be received: this switching is requested by
a decoder 24 over an upstream channel driven by a command transmitter 26 and interpreted
and executed by a command receiver 25.
[0038] The signals are carried from the first adder 20, over the telephone wire pair 9,
to a second adder or adder-splitter 22, which is located at the individual user and
splits the signal, sending it to an additional modulator-demodulator (ADSL modem)
29 and then to a television set 8 and to a telephone 10; as an alternative, the signals
are carried from the first adder 20, over the telephone wire pair 9, to a second adder-splitter
22 which is located at the individual user and splits the signal, sending it to a
telephone 10 and to a demodulator 39 which is located inside the decoder 24 and then
to a television set 8.
[0039] The method for transmitting the signals from the first adder to the second adder
over the telephone wire pair 9 may be the most convenient and therefore may use the
following systems:
-- a transmission technology using a 'broadband asymmetric transmission system' (ADSL),
which splits the information to be transmitted into a large number of small packets
to be transmitted (ADSL DMT or Discrete Multi Tone);
-- an alternative transmission technology using a 'broadband asymmetric transmission
system' (ADSL) (ADSL CAP or Carrierless Amplitude Modulation);
-- a modulation system used for digital transmission over broadband cable networks
(ADSL QAM or Quadrature Amplitude Modulation);
-- a system that differs from the 'broadband asymmetric transmission system' (ADSL)
in that it provides symmetrical communication in the upstream and downstream channels
(HDSL or High Speed Digital Subscriber Loop);
-- a system which differs from the preceding one in terms of a higher transmission
rate (VDSL or Very High Speed Digital Subscriber Loop);
-- wireless transmission at radio frequencies (narrowband wireless);
-- transmission with methods known as "spread-spectrum".
[0040] The illustrated solutions therefore allow to achieve all the advantages that can
be individually ascribed to known technology without requiring interventions such
as the addition of further cables, wiring and masonry work, with consequent cost reductions
and elimination of the previously mentioned inconveniences.
[0041] Figure 5 is a block diagram of an indication of a possible method of operation. The
user selects a channel with remote control of decoder (step 100). The decoder receives
signal of remote control and sends a tuning request to the front end in fiber node
over an upstream channel (step 101). The ADSL modem in user's home sends request over
the telephone wire pair and simultaneously ensures normal telephone service (step
102). The ADSL modem in fiber mode receives the upstream channel and sends it to the
front end module (step 103). The microprocessor in front end module tunes into the
chosen channel and sends it over a downstream channel to the user for viewing (step
104).
[0042] Figures 6 and 7 are block diagrams of the device of the present invention.
[0043] Figures 8 and 9 are flow charts of further possible methods of operation. The user
selects a channel with remote control of decoder (step 105). The decoder receives
the signal of remote control and uses command transmitter to transmit, over the telephone
wire pair, tuning request to the front end module located either proximate to fiber
node or in basement closets (for example basements or meter closets) (step 106). The
command receiver receives the channel tuning request and selects the channel by means
of the front end. The front end converts the channel into data stream and sends it
to the modulator (step 107). The modulator modulates the data stream and sends it
over the telephone wire pair (step 108). The demodulator module located in the decoder
receives modulated data from the wire pair and converts them back to data which are
processed by the rest of the decoder until display of picture on television set is
achieved (step 109).
[0044] The method shown in Figure 9 instead provides for the following steps. The user selects
a channel with remote control of the decoder (step 105). The decoder receives signal
of the remote control and uses command transmitter to transmit, over the telephone
wire pair, tuning request to the front end module located either proximate to fiber
node or in basement closets (for example basements or meter closets) (step 106). The
command receiver receives the channel tuning request and selects the channel by means
of the front end. The front end converts the channel into a standard fixed-frequency
channel without altering its modultion and sends it over the telephone wire pair after
amplification (step 107). The demodulator module located in the decoder receives modulated
data from the wire pair and converts them back to data which are processed by the
rest of the decoder until display of picture on television set is achieved (step 111).
[0045] It has thus been observed that the illustrated method has achieved all of the intended
aim and objects, since it is possible to distribute broadband services to the various
users, eliminating the costs and inconveniences of laying coaxial-cable to reach the
user.
[0046] Attention is also drawn to the fact that the switching system located in the utility
closets of the building can be controlled, for example, by means of a conventional
telephone modem which is included by the service provider, so as to enable or disable
the supply of the service, and thus becomes the system for conditional access to the
service.
[0047] It is noted that the switching system according to the present method can be supplied
by various power sources, such as electric mains power, over the coaxial cable of
the broadband network, by means of the telephone wire pair of the telephone system,
by means of the set-top box (decoder) using the wire pair section that connects the
set-top box to the switching system.
[0048] The present invention is of course susceptible of numerous modifications and variations,
all of which are within the scope of the same inventive concept.
[0049] For example, the front end 12 might directly accept a fiber-optic input, avoiding
optoelectrical conversion at the fiber node side, with an additional economical advantage.
[0050] The materials and the dimensions that constitute the individual components used in
the illustrated solutions, as well as the method for transmitting the signals to the
second adder, may of course also be the most pertinent according to specific requirements.
[0051] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A method for distributing broadband services,
characterized in that it comprises the steps of:
- separating a broadband front end (12) of a receiver circuit (11) from other portions
of the circuit;
- placing said front end (12) in utility closets of a building;
- connecting said front end (12) to a modulator-demodulator (19) or to a modulator
(23) or to an amplifier;
- transferring a signal from said modulator - demodulator (19) or from said modulator
(23) or from said amplifier and the signal from a telephone exchange (21) to a first
adder (20) in order to mix the broadband and telephone services;
- transferring signals from said first adder (20) over a telephone wire pair (9) to
an individual end user;
- splitting the signals to a telephone (10) and to a television set (8).
2. The method according to claim 1, characterized in that said broadband front end (12) of said receiver (11), separated from the other portions
of said circuit, is located in a fiber node (2) and to the point of a broadband hybrid
fiber-coaxial HFC network where the optical signal arriving from the fiber is converted
into an electrical signal for transmission on coaxial cable.
3. The method according to claim 2, characterized in that said front end (12) is connected to the coaxial cable of said fiber node (2).
4. The method according to claim 1, characterized in that the signals are carried from said first adder (20) over the telephone wire pair (9)
to a second adder (22) located at the individual user, which splits the signal and
transfers it to an additional modulator-demodulator (29) and then to the television
set (8) and to the telephone (10).
5. The method according to claim 4,
characterized in that the method for transmitting the signals between said first and second adders (20,
22) over said telephone wire pair occurs with a method chosen among:
- transmitting using a 'broadband asymmetric transmission system', which splits the
information to be transmitted into a large number of small packets to be transmitted;
- transmitting using a 'broadband asymmetric transmission system';
- modulating the signals by means of a modulation system used for digital transmission
over broadband cable networks;
- providing symmetrical communication in the upstream and downstream channels;
- transmitting using a spread spectrum technique.
6. The method according to claim 1, characterized in that said broadband front end (12) of said receiver (11), separated from the rest of said
circuit, is located in a chosen point of a house reached by the telephone wire pair
(9).
7. The method according to claim 6, characterized in that said front end (12) is connected to said modulator (19), which in turn sends the
signal to said first adder (20) which also receives a signal from the telephone exchange
(21).
8. The method according to claim 7, characterized in that said front end (12) is connected to said amplifier, which in turn sends the signal
to said first adder (20), which also receives a signal from the telephone exchange
(21).
9. The method according to claim 8, characterized in that said front end (12) selects a channel to be received, said selection being requested
by a decoder (24) over an upstream channel driven by a command transmitter (26) and
being interpreted and executed by a command receiver (25).
10. The method according to claim 9, characterized in that it comprises the step of implementing, by said command receiver (25), data from a
telephone network so that said command receiver (25) also acts as a system for conditional
access to the broadband network.
11. The method according to claim 10, characterized in that the signals are transferred from said first adder (20) over the telephone wire pair
(9) to said second adder (22) located at the individual user, which splits the signal
and transfers it to a demodulator (39) which is located inside said decoder and then
to the television set (8).
12. The method according to claim 11, characterized in that the method for transmitting the signals between said first and second adders (20,
22) over said telephone wire pair (9) is a transmission method using a spread spectrum
technique.
1. Ein Verfahren zur Verteilung von Breitbanddiensten,
dadurch gekennzeichnet, dass es die folgenden Schritte umfasst:
- Abtrennen eines Breitband-Front-Ends einer Empfängerschaltung (11) von anderen Teilen
der Schaltung;
- Platzieren des Front-Ends (12) in Verteilerschränke eines Gebäudes;
- Verbinden des Front-Ends (12) mit einem Modulator/Demodulator (19) oder mit einem
Modulator (23) oder mit einem Verstärker;
- Übertragen eines Signals vom Modulator/Demodulator (19) oder vom Modulator (23)
oder vom Verstärker und des Signals vom Fernsprechamt (21) an einen ersten Addierer
(20), um die Breitband- und Fernsprechdienste zu mischen;
- Übertragen von Signalen des ersten Addierers (20) über eine Telefon-Doppeladerleitung
(9) zu einem individuellen Endbenutzer.
- Aufspalten der Signale zu einem Telefon (10) und zu einem Fernseher (8).
2. Das Verfahren gemäß Anspruch 1, dadurch gekennzeichnet, dass das von den anderen Teilen der Schaltung getrennte Breitband-Front-End (12) des Empfängers
(11) in einem Glasfaserknoten (2) angeordnet ist und bis zu dem Punkt eines hybriden
Glasfaser-Koaxial-HFC-Breitbandnetzwerks, an dem das optische Signal von der Glasfaser
ankommt in ein elektrisches Signal zur Übertragung auf Koaxialkabel umgewandelt wird.
3. Das Verfahren gemäß Anspruch 2, dadurch gekennzeichnet, dass das Front-End (12) mit dem Koaxialkabel des Glasfaserknotens (2) verbunden ist.
4. Das Verfahren gemäß Anspruch 1, dadurch gekennzeichnet, dass die Signale vom ersten Addierer (20) über die Telefon-Doppeladerleitung (9) zu einem
zweiten Addierer (22), der beim individuellen Benutzer angeordnet ist, übertragen
werden, der das Signal aufspaltet und es an einen zusätzlichen Modulator/Demodulator
(29) überträgt und dann an den Fernseher (8) und an das Telefon (10) überträgt.
5. Das Verfahren gemäß Anspruch 4,
dadurch gekennzeichnet, dass das Verfahren zum Übertragen der Signale zwischen dem ersten und zweiten Addierer
(20, 22) über die Telefon-Doppeladerleitung erfolgt, mit einem Verfahren ausgewählt
aus:
- Übertragung mittels eines "asymmetrischen Breitbandübertragungssystems", das die
zu übertragenden Informationen in viele kleine zu übertragende Pakete aufspaltet;
- Übertragung mittels eines "asymmetrischen Breitbandübertragungssystems";
- Modulieren der Signale mit Hilfe eines für digitale Übertragung über Breitbandkabelnetzwerke
verwendeten Modulationssystems;
- Bereitstellen symmetrischer Kommunikation in den Upstream- und Downstreamkanälen;
- Übertragung mittels eines Bandspreizverfahren.
6. Das Verfahren gemäß Anspruch 1, dadurch gekennzeichnet, dass das Breitband-Front-End (12) des Empfängers (11), getrennt vom Rest der Schaltung,
in einem ausgewählten Punkt eines Hauses angeordnet ist, das von der Telefon-Doppeladerleitung
(9) versorgt wird.
7. Das Verfahren gemäß Anspruch 6, dadurch gekennzeichnet, dass das Front-End (12) an einem Modulator (19) angeschlossen ist, der abwechselnd das
Signal zum ersten Addierer (20), der auch ein Signal vom Fernsprechamt (21) empfängt,
sendet.
8. Das Verfahren gemäß Anspruch 7, dadurch gekennzeichnet, dass das Front-End (12) an einen Verstärker angeschlossen ist, der abwechselnd das Signal
zum erster Addierer (20), der auch ein Signal vom Fernsprechamt (21) empfängt, sendet.
9. Das Verfahren gemäß Anspruch 8, dadurch gekennzeichnet, dass das Front-End (12) einen zu empfangenden Kanal auswählt, wobei die Auswahl von einem
Dekoder (24) über einen von einem Befehlsübertrager (26) gesteuerten Upstream-Kanal
angefordert wird und von einem Befehlsempfänger (25) interpretiert und ausgeführt
wird.
10. Das Verfahren gemäß Anspruch 9, dadurch gekennzeichnet, dass es den Schritt des Umsetzens von Daten von einem Telefonnetzwerk durch einen Befehlsempfänger
(25) umfasst, damit der Befehlsempfänger (25) auch als ein System für die Zugangsberechtigung
zum Breitbandnetzwerk fungiert.
11. Das Verfahren gemäß Anspruch 10, dadurch gekennzeichnet, dass die Signale vom ersten Addierer (20) über die Telefon-Doppeladerleitung (9) an einen
zweiten Addierer (22), der beim Benutzer angeordnet ist, übertragen werden, der das
Signal aufspaltet und es an einen Demodulator (39) überträgt, der innerhalb des Dekoders
angeordnet ist, und dann an ein Fernsehgerät überträgt.
12. Das Verfahren gemäß Anspruch 11, dadurch gekennzeichnet, dass das Verfahren zum Übertragen der Signale zwischen dem ersten und zweiten Addierer
(20, 22) über die Telefon-Doppeladerleitung (9) ein Bandspreizverfahren verwendendes
Übertragungsverfahren ist.
1. Procédé de distribution de services à large bande,
caractérisé en ce qu'il comprend les étapes consistant à:
- séparer une borne frontale à large bande (12) d'un circuit de récepteur (11) des
autres parties du circuit;
- placer ladite borne frontale (12) dans les locaux techniques d'un édifice;
- connecter ladite borne frontale (12) à un modudateur-démodulateur (19) ou à un modulateur
(23) ou à un amplificateur;
- transférer un signal depuis ledit modulateur-démodulateur (19) ou depuis ledit modulateur
(23) ou depuis ledit amplificateur et le signal depuis un central téléphonique (21)
à un premier additionneur (20) afin de mélanger les services à large bande et les
services téléphoniques;
- transférer les signaux depuis ledit premier additionneur (20) à travers une ligne
bifilaire téléphonique (9) à un utilisateur final individuel;
- diviser les signaux au téléphone (10) et à la télévision (8).
2. Procédé selon la revendication 1, caractérisé en ce que ladite borne frontale à large bande (12) dudit récepteur (11), séparé des autres
parties dudit circuit, est situé dans un noeud de fibres (2) et au point d'un réseau
hybride à large bande et à fibre coaxiale HFC où le signal optique arrivant de la
fibre est converti en un signal électrique pour la transmission sur un câble coaxial.
3. Procédé selon la revendication 2, caractérisé en ce que ladite borne frontale à large bande (12) est connectée au câble coaxiale dudit noeud
de fibre (2).
4. Procédé selon la revendication 1, caractérisé en ce que les signaux sont transportés depuis ledit premier additionneur (20) à travers la
ligne bifilaire téléphonique (9) à un deuxième additionneur (22), situé chez un utilisateur
individuel, qui divise le signal et le transfert à un modulateur-démodulateur supplémentaire
(29) et ensuite à la télévision (8) et au téléphone (10).
5. Procédé selon la revendication 4,
caractérisé en ce que le procédé de transmission des signaux entre lesdits premier et deuxième additionneurs
(20, 22) à travers ladite ligne bifilaire téléphonique a lieu avec un procédé choisi
parmi les suivants:
- transmettre en utilisant un "système de transmission asymétrique à large bande",
qui divise l'information à transmettre en un large nombre de petits paquets à transmettre;
- transmettre en utilisant un "système de transmission asymétrique à large bande";
- moduler les signaux au moyen d'un système de modulation utilisé pour la transmission
de données à travers des réseaux de câble à large bande;
- fournir une communication symétrique dans les canaux en amont et en aval;
- transmettre en utilisant une technique à fréquence étendue.
6. Procédé selon la revendication 1, caractérisé en ce que ladite borne frontale à large bande (12) dudit récepteur (11), séparée du reste dudit
circuit, est située dans un point choisi de la maison atteint par la ligne bifilaire
téléphonique (9).
7. Procédé selon la revendication 6, caractérisé en ce que ladite borne frontale (12) est connectée audit modulateur (19) qui à son tour envoie
le signal audit premier additionneur (20) qui reçoit également un signal du central
téléphonique (21).
8. Procédé selon la revendication 7, caractérisé en ce que ladite borne frontale (12) est connectée audit amplificateur qui à son tour envoie
le signal audit premier additionneur (20) qui reçoit également un signal du central
téléphonique (21).
9. Procédé selon la revendication 8, caractérisé en ce que ladite borne frontale (12) sélectionne un canal devant être reçu, ladite sélection
étant requise par un décodeur (24) à travers un canal en amont actionné par un transmetteur
de commande (26) et étant interprété et exécuté par un récepteur de commande (25).
10. Procédé selon la revendication 9, caractérisé en ce qu'il comprend l'étape consistant à mettre en application, par ledit récepteur de commande
(25), des données depuis un réseau téléphonique de sorte que ledit récepteur de commande
(25) agisse également comme un système pour l'accès conditionnel au réseau à large
bande.
11. Procédé selon la revendication 10, caractérisé en ce que les signaux sont transférés depuis ledit premier additionneur (20) à travers la ligne
bifilaire téléphonique (9) audit deuxième additionneur (22), situé chez l'utilisateur
individuel, qui divise le signal et le transfert à un démodulateur (39) qui est situé
à l'intérieur dudit décodeur et ensuite à la télévision (8).
12. Procédé selon la revendication 11, caractérisé en ce que le procédé de transmission des signaux entre lesdits premier et deuxième additionneurs
(20, 22) à travers ladite ligne bifilaire téléphonique (9) est un procédé de transmission
utilisant une technique à fréquence étendue.