ES2361104B1 - OPTICAL NETWORK TERMINAL. OPTICAL TERMINATOR OF LINE AND METHOD OF TRANSMISSION / RECEPTION OF DIGITAL TELEVISION CHANNELS IN A PASSIVE OPTICAL NETWORK. - Google Patents

Abstract

Optical network terminal, optical line terminator and method of transmitting / receiving digital television channels in a passive optical network. # Optical network terminal with at least one optical input / output port and a radio frequency output port with the means for extracting a radiofrequency signal emitted by a line optical terminator through a passive optical network, filtering a subset of digital television channels contained in said signal, and emitting a radiofrequency signal with said channels through the port radio frequency output; optical line terminator with the means to broadcast digital television channels through the passive optical network and remotely manage the filtering process; and method of transmission / reception of digital television channels between the optical line terminator and the optical network terminal that regulates said transmission and filtering.

Description

Optical network terminal, optical line terminator and method of transmission / reception of digital television channels in a passive optical network.

Field of the Invention

The present invention applies to the field of telecommunications and, more specifically, to communications in passive optical networks.

Background of the invention

The deployment of optical communications networks with PON technologies (in English, Passive Optical Network), such as GPON (in English, Gigabit capable PON), EPON (in English, Ethernet PON), BPON (in English, Broadband PON) is beginning to begin ) and its variants.

In general, a PON network is composed of at least one optical line terminator (OLT) 1, an optical distribution network with at least one optical splitter 3 and several optical network terminal modules ( ONTs, from the English Optical Network Terminal) 2. OLT 1 is responsible for managing the network, carrying out assignments of resources, synchronization, remote configuration and, where appropriate, dissemination of the contents of an operator. For this, it has an optical receiver 5 and a transmitter 6, connected to a wavelength multiplexer 4, as well as the control logic 7 necessary to operate them. OLTs capable of broadcasting television content also comprise a video transmitter 8, connected to a second wavelength multiplexer 9.

The complementary structure is in the ONT 2, with an optical transmitter 12 and receiver 13 connected to a wavelength multiplexer 10, and in the case of an ONT capable of receiving said video contents, a video receiver 15 also connected to said wavelength multiplexer 10. The control logic 11 also comprises operating said elements and, optionally, a wavelength blocking filter 14, and a wavelength blocking filter for video 16.

Within the PON family of networks, standards have evolved to GPON technology, which has a greater bandwidth than its predecessors, as well as greater efficiency in the use of the channel. In line with what happened with BPON technology, in 2007 an improvement band for GPON-based optical access was defined (ITU-T G.984.5).

In parallel, the transmission of television channels has undergone a remarkable evolution in recent years that has taken it from traditional analog television to new digital formats, such as digital terrestrial television (DTT, or according to the English nomenclature, DVB-T , Digital Video Broadcasting Terrestrial). The way of choosing audiovisual content in these networks has also been subject to changes, with an increasing weight of the Pay Per Vision services (hereinafter PPV), in which the user selects those contents that he wishes to have in his terminal, paying exclusively for such content.

In general, DTT channels are multiplexed in a transmission stream (TS). These TS, are modulated in QAM (English, Quadrature Amplitude Modulation), and are transported by a series of carrier signals thus forming a structure of radio frequency channels.

The transmission of DTT through the traditional infrastructure of radiofrequency repeaters has associated a series of classic problems such as coverage or the different level of signal received depending on the position of the receiving equipment.

The use of passive optical networks for the diffusion of digital television content allows to solve these problems. For example, CN101018311 presents a method to inject DVB-T content into an EPON network. The limitations of these systems come from part of the bandwidth provided by the network depending on its architecture, and on the other hand, from the broadcast nature of the PONs, in which all ONTs have access to it. channel, and therefore receive the same data fl ow (although the information can then be separated by encryption).

Thus, all users of a digital television content dissemination system through PON networks will be subject to the reception of the same channels, so that for the implementation of pay-per-view services, some capable external equipment will be required. of implementing those functions independently to the PON network itself.

Summary of the Invention

The present invention solves the aforementioned problem by means of an optical network terminal (ONT), connectable to a passive optical network (PON) by means of an optical input / output port and a conventional Digital Terrestrial Television (DTT) television or receiver via a port of radio frequency output, capable of fi ltering a set of digital television channels from a signal from said PON network. To do this, the ONT first extracts from the optical signal emitted by an optical line terminator (OLT), a radio frequency signal that carries the broadcast digital television channels. Then, it performs a selective filtering, so that a subset of channels are selected, which will be those received by the ONT user. Said filtering is tunable, that is, it does not remain static over time but can be modified in order to select different subsets of channels at different times. Finally, the selected subset of channels will be converted to a radio frequency signal in which the rest of the channels are no longer found, and said signal will be emitted through the radio frequency output port so that it can be received by the DTT receiver (It is already integrated into a television or a separate device).

The channel filtering will preferably comprise two tunable pass-band filters that act in parallel. The first of the filters will be responsible for separating the digital television channels destined for all the users of the network, filtering the set of transmission channels that carry transmission flows on which said channels are multiplexed. The second fi lter is dedicated to pay-per-view services, so the filtering depends on the services contracted at that moment by the ONT user. This second fi ltrate will therefore have a lower bandwidth, restricting itself to the radio frequency channels that carry transmission fl ows on which the pay-per-view channels contracted by the user are multiplexed. The ONT will therefore have the necessary means of control to manage both filters.

In order to isolate the payment channels contracted by the user from the rest of the information contained in the radio frequency channels selected by the second fi lter, the ONT will also preferably have a digital television receiver capable of demodulating the transmission streams contained in said radio frequency channels. By means of a demultiplexer, each transmission fl ow will be separated into the different digital television channels that it carries, from which the digital television channel that has been contracted by the user will be selected, discarding the rest of the channels. The selected channel, together with a filler content, will form a new transmission fl ow, whose generation will be commissioned by a multiplexer. Once the transmission fl ow that only contains the contracted channel is available, it is modulated to be incorporated into the radio frequency signal with the general channels separated by the first tunable pass-band fi lter.

One of the preferred options for the management and con fi guration of the filtering processes described is based on the use of manageable entities in the ONT, which the OLT may remotely configure through the control and management interface of the network optical terminal (OMCI, from the English ONT Management Control Interface). These manageable entities will contain the necessary parameters to determine the performance of the fi lters (bandwidth, operating frequencies, etc ...).

If this option is used, the use of manageable entities can be extended, preferably, in order to comprise manageable entities that contain the information necessary to charge the payment-per-view services requested by the user. The operator may access this information from the OLT through the OMCI channel.

Another preferred option for the management and con fi guration of the fi ltered processes is based on the inclusion of a Near Field Communications Microcontroller (NFC), so that the fi ltrate can be con fi gured through a device external communications (for example a mobile phone). In this way, the operator will be able to send to the ONT the configuration information that it needs to perform the described filtering, using resources external to the PON network.

Preferably, in all the cases described above, the radio frequency channels on which the filtering is performed will be extracted from an improvement band for optical access based on passive optical networks with gigabit capacity, such as the one defined by the International Telecommunication Union in document G.984.5.

In another aspect of the present invention, the complementary transmitter equipment is presented, that is, an OLT with the means for broadcasting digital television channels through a passive optical network (that is, multiplexing said digital television channels in the corresponding flows of transmission, which in turn are modulated in a series of radio frequency channels), and to remotely manage the corresponding filtering of digital television channels that will take place in the ONT. This management supports different options as described above, among which are the use of manageable entities of the ONT and communication through external equipment to the PON network (using near-field communications to communicate said equipment with the ONT).

Also in a complementary manner, the OLT of the invention will emit said modulated radio frequency channels in an optical signal using, preferably, the improvement band for optical access based on passive optical networks with gigabit capacity.

In another aspect of the invention, a method is presented for the transmission and reception of digital television channels over a passive optical network, including pay-per-view services that the user may request from an operator. Said method begins with the multiplexing of digital television channels in the corresponding transmission flows, which in turn are modulated in radio frequency channels and sent through the passive optical network. Already at the end of the user, said radio frequency channels are fi ltered, then recovering the digital television channels contained therein. Then, those channels that correspond to broadcast services to all users, or pay-per-view services requested by the user, are discarded, discarding the rest of the channels. Channels that are not discarded are used to reconstruct a radio frequency signal that will be transmitted to a digital terrestrial television decoder external to the PON network, either in the form of independent equipment or integrated into a television.

Preferably, the sending of radio frequency channels will be carried out on the improvement band for optical access based on passive optical networks with gigabit capacity.

Also preferably, the described method will have a management system based on the use of networks external to the PON network itself. For this, an ONT will request the OLT to transmit content corresponding to a digital pay-per-view television service. The operator of said service will use a text message to send the corresponding configuration information to a mobile device associated with the ONT. Finally, the mobile device will share this information with the ONT through a near-field communication connection, thanks to which said ONT can correctly perform the corresponding filtering and provide the user with the pay-per-view digital television channel that he had hired.

These and other advantages will be apparent in view of the detailed description of the invention.

Brief description of the fi gures

In order to help a better understanding of the features of the invention according to a preferred example of practical realization thereof and to complement this description, the following figure is attached as an integral part thereof, which is illustrative and not limiting:

Figure 1 shows a scheme of a conventional passive optical network (PON).

Figure 2 shows the elements to be added to a conventional optical network terminal (ONT) for carrying out the present invention.

Detailed description of the invention

Figure 2 shows the elements that the present invention incorporates to those of a conventional ONT. Said functional blocks act on a radio frequency signal extracted from the optical signal that transports it through the PON network. In the preferred embodiment, the improvement band for GPON access defined by ITU in its Recommendation G.984.5 is used for said transmission, although the subsequent data processing is transparent to the PON link technology.

As indicated by the present invention, the ONT has two tunable pass-band filters that act in parallel:

-

A narrow pass-band fi lter 18 that selects the radio frequency (RF) channel modulated in QAM (quadrature amplitude modulation) that conveys the transmission fl ow (TS) on which a user-requested pay-per-view service is multiplexed .

-

A wider 17-band-pass fi lter that selects all radio frequency channels modulated in QAM that contain television channels intended for all users.

Once the RF channel with the TS where the pay-per-view channel selected by the user goes, the selected channel of said multiplex has to be recovered, and once recovered, a new TS has to be generated again that transports Only the selected channel, plus a fill. This new TS will be used to modulate the carrier of the channel again in QAM, a digital television receiver 19 is included that allows demodulating said TS, a demultiplexer 20 to separate said TS into the channels that comprise it and, to perform the Inverse process once the desired channel is separated and the filling content is incorporated, a multiplexer 21 to form the new TS and a QAM23 modulator to modulate said TS in a radiofrequency channel.

Subsequently, the RF fl ow from the two fi lters are summed by an adder or combiner 24, generating a new RF multiplex with the open and pay-per-view channels contracted by the client, so that the DTT receiver incorporated by the The client's television receiver is responsible for decoding the channels transported by the new RF multiplex generated by the ONT.

In order for the invention to be translated into a commercial pay-per-view (PPV) service without the need to include a decoder, the tuning frequencies of the two bandpass filters must be indicated to the ONT in some way. For this, in this proposal, two alternatives are proposed.

The first alternative involves using new manageable entities through GPON's OMCI channel, the channel through which OLT manages the connected ONTs. The purpose of these new manageable entities is to be able to indicate to each ONT (user) the channel in PPV that can be tuned to receive the content (channel) demanded. These entities are not covered by current standards (ITU-T G.983.4) and should be included, or resort to proprietary implementation.

The second alternative is based on the inclusion in the ONT of an NFC microcontroller that allows to receive, via NFC a code that will be used by the ONT 22 control to tune the bandpass filter and extract the digital channel in PPV requested by the user . The end user, through the mobile terminal with NFC support, can send to the NFC microcontroller of the ONT the necessary information for the tuning and extraction of the desired DTT content.

Going deeper into the first of the alternatives, a managed entity like the one raised in the patent application is not contemplated in ITU-T G.983.4. Therefore, a new managed entity that contemplates this scenario should be considered. And within that managed entity, at least four new attributes must be defined:

-

Start frequency of the open channel band (channels broadcast to all network users), that is, the band corresponding to BTV (Broadcast TV). This will be a default parameter or attribute, whose value will be set by the GPON access operator based on the set of channels it is transmitting and the spectrum that said channel multiplex is occupying.

-

Frequency of finalization of the open channel band, that is, the band corresponding to BTV (Broadcast TV). As in the previous case, this will be an attribute with a default value, whose value will be set by the GPON access operator based on the set of channels it is transmitting and the spectrum that said channel multiplex is occupying.

-

Start frequency of the requested PPV channel. The invention is transparent to the selection mechanism used, which may be via an IP application through the conventional upstream channel,

or through the return channel, if this is enabled. In the latter case, to continue maintaining the absence of an external decoder, the functionalities of the video return channel will be included in the ONT itself.

-

Channel bandwidth in PPV requested, to contemplate possible frequency plans at 6 MHz (ANSI / ATIS) u8MHz (ETSI). As in the first two attributes, this will take a default value, depending on the standard in force in the country where it operates.

In DVB-T (DTT), each RF channel carries a transport stream TS consisting of N channels (for example, between 4 and 8 with MPEG2, depending on whether they are of high definition or standard definition). Therefore, to extract a channel, an additional parameter, a pointer, is required to select the individual channel to be provided to the user, and which will then serve as a basis, together with a padding, to generate the new TS in the same RF channel that will be added to the output signal delivered by the ONT through its coaxial interface.

This scheme also allows the commercialization of packages of pay-TV channels, in which case the pointer must have a default value that allows the delivery of all TS channels contained in the tuned RF channel to the user's receiver.

Since this type of content is ephemeral in nature (sports broadcasts, bullfighting, live events such as concerts, ...), the opening of the channel so that it can be received by the user should only be valid for a limited period of time. For this reason, the managed entity must contain in the form of attributes the start time of the content contracted in PPV, as well as its duration.

Finally, the managed entity must also manage the password used to secure the content.

The second of the mentioned options does not require the creation of new manageable entities on GPON's OMCI channel. In this case the information necessary to tune the channel in PPV, which will be the same as indicated in the previous option, will be received via NFC, for example, from a mobile phone with NFC support. This information will be transferred by the NFC microcontroller installed in the ONT, to the ONT processor, which in turn will act on the tunable bandpass filters and the ONT multiplexer and demultiplexer.

To identify the content you selected, the following parameters are required:

-

Frequency of the DVB-T channel with the TS containing the requested content.

-

Associated channel within the TS.

-

Start time and duration of the content.

-

User identification (USERID) of the IPTV service (associated, for example, with an MSISDN, of the English Mobile Station International Subscriber Directory Number, in the service database).

-

Identifier of the ONT (HARDWARE ID, such as the serial number).

-

Key used for content security.

The NFC hardware required in the ONT for the implementation of this control option is an NFC microcontroller with the ability to operate in read / write mode and with an API (English, Application Programming Interface) to develop the NFC application.

The present preferred embodiment considers two content purchase scenarios using this second method:

-

Purchase without mobility, in which the user who buys is the owner of the ONT. In this case, the action procedure would be as follows: the user makes use of the navigation guide offered by the service to select the purchase of a content. At the moment the user completes the purchase, the ONT activates the NFC application and generates a request to the network indicating the ONT HARDWARE ID (internally stored), the USERID (internally stored) and the selected content. The purchase platform, upon receiving said purchase request, first identifies the user and obtains the MSISDN associated with it, and then generates and sends to said MSISDN an SMS PP (Point-to-Point SMS message coded by the operator and that the The user does not have the possibility to see since it goes directly to the card) with the parameters required by the ONT to allow the visualization of the content. Once the user has received the message (he will receive a notification, for example a visual indication), he should only approach the terminal to the NFC controller of the ONT to transmit said parameters. Finally, the ONT applies these parameters and allows the display of the content.

-

Purchase with mobility, in which the user who buys is a visitor and different from the owner of the ONT. Here the action procedure is as follows. As in the previous case, the user makes use of the navigation guide offered by the service to select the purchase of a content. However, at the time the user completes the purchase, the ONT activates the NFC application and waits for the user to approach his NFC terminal to know the USERID against which he will charge the purchase. Once this identifier is available, it generates the request to the network indicating the ONT HARDWARE ID (stored internally), the USERID (acquired through NFC) and the selected content. As of this moment, the process is the same as in the previous case. The purchase platform, upon receiving said purchase request, first identifies the user and obtains the MSISDN associated with it, and then generates and sends to said MSISDN an SMS PP with the parameters required by the ONT in order to allow the display of the content. Once the user has received the message, they should only approach the terminal to the NFC microcontroller of the ONT and transmit said parameters. Finally, the ONT applies these parameters and allows the display of the content.

In view of this description and figure, the person skilled in the art may understand that the invention has been described according to some preferred embodiments thereof, but that multiple variations can be introduced in said preferred embodiments, without departing from the object of the invention such and as claimed.

Claims (11)

1. Optical network terminal with at least one optical input / output port and a radio frequency output port characterized in that it comprises means for:

-

extracting, from a signal emitted by an optical line terminator of a passive optical network and received through said optical input / output port, a first radio frequency signal that carries a plurality of digital television channels;

-

performing, on said first radio frequency signal, a selective tunable filtering of digital television channels transported by said signal; Y

-

emitting from said radio frequency output port a second radio frequency signal carrying said fi ltered digital television channels.

Where the means to perform said selective filtering include:

-

a first tunable pass-band fi lter (17), configured to extract, from said first radiofrequency signal, a plurality of radio frequency channels that carry transmission streams on which multiplexed digital television channels are broadcast to all users of the passive optical network;

-

a second tunable pass-band fi lter (18), which operates in parallel to said first tunable pass-band fi lter (17), configured to extract, from said first radiofrequency signal, a radiofrequency channel carrying a transmission fl ow on the that a digital television channel corresponding to a pay-per-view service requested by a user of said optical network terminal is multiplexed;

-

control means (22) for con fi guring said first tunable pass-band fi lter (17) and said second tunable pass-band fi lter (18).

-

a digital television receiver (19) configured to demodulate a transmission fl ow from the radio frequency channel extracted by the second tunable pass-band fi lter (18);

-

a demultiplexer (20) configured to select, from among a multiplexed digital television channels in said transmission stream demodulated by the digital television receiver (19), a digital television channel corresponding to a pay-per-view service requested by a user of said optical network terminal;

-

a multiplexer (21) configured to generate a new transmission fl ow from the digital television channel selected by the demultiplexer (20), corresponding to the pay-per-view service requested by the user, and a filler content;

-

a modulator (23) configured to modulate said new transmission fl ow in a radio frequency channel.

2.

Optical network terminal according to claim 1, characterized in that the control means (22) for configuring said first tunable band-pass fi lter (17) and said second tunable band-pass fi lter (18) comprise at least a first manageable entity comprising a plurality of attributes for determining said configuration, said attributes being controlled by the optical line terminator through the control and management channel of the network optical terminal of a passive optical network with gigabit capacity.

3.

Optical network terminal according to claim 2, characterized in that the control means (22) for configuring said first tunable band-pass fi lter (17) and said second tunable band-pass fi lter (18) further comprise a second manageable entity comprising a plurality of attributes used by an operator to perform a fee payment per vision service requested by the user, said attributes being controlled by the optical line terminator through the control and management channel of the network optical terminal of a network passive optics with gigabit capacity.

Four.

Optical network terminal according to claim 1, characterized in that the control means (22) for configuring said first tunable band-pass fi lter (17) and said second tunable band-pass fi lter (18) comprise at least one communications microcontroller of near field with capacity to operate in read / write mode, said near field communications microcontroller being configured to receive con fi guration information from an external mobile equipment to the passive optical network.

5.

Optical network terminal according to any one of the preceding claims, characterized in that said first radio frequency signal is made on an improvement band for optical access based on passive optical networks with gigabit capacity.

6.

Optical line terminator characterized in that it comprises means for: -multiplexing digital television channels in transmission flows; - modulate said transmission fl ows in radiofrequency channels; - emitting said modulated radio frequency channels in an optical signal through a passive optical network; - Remotely manage a tunable selective filtering of digital television channels that takes place in a

network optical terminal connected to the optical line terminator through a passive optical network.

7.

Optical line terminator according to claim 6 characterized in that it emits said modulated radio frequency channels in an optical signal using an improvement band for optical access based on passive optical networks with gigabit capacity.

8.

Method for the transmission / reception of digital television channels, including pay-per-view services requested by a user, in a passive optical network, comprising: -multiplexing said digital television channels in a set of transmission flows; - sending said modulated transmission fl ows in radio frequency channels, through said passive optical network; -that is to filter said radio frequency channels into an optical network terminal; -recover the digital television channels contained in the modulated transmission fl ows in the filtered radiofrequency channels; - Discard those recovered digital television channels that do not correspond to channels broadcast to all users or to pay-per-view services requested by the user of said optical network terminal;

-reconstruct a radio frequency signal formed by those channels that have not been discarded; -transmit the reconstructed radio frequency signal to an external digital television decoder.

9.

Method according to claim 8, characterized in that said radio frequency channels are sent using an improvement band for optical access based on passive optical networks with gigabit capacity.

10. Method according to any claim 8 and 9 characterized in that it further comprises:

-

request from a network optical terminal, to a line optical terminal equipment, the transmission of a digital television content for pay-per-view;

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send, at least, a text message to a mobile device associated with a user of said optical network terminal, with information necessary to filter said digital pay-per-view television content;

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transmitting said information from said mobile device to the network optical terminal, through a near field communication connection.

  ���������������   SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 200930023 SPAIN Date of submission of the application: 03.31.2009 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: H04B10 / 1 (2006.01) H04J14 / 02 (2006.01) RELEVANT DOCUMENTS

Category

Documents cited Claims Affected

X

US 5790170 A (SUZUKI MITSUHIRO) 04.08.1998, column 1, lines 7-10; column 1, 1-10

line 17 - column 2, line 15; column 5, line 55 - column 6, line 14; column 8,

line 39 - column 9 line 5; column 9, line 36 - column 12, line 20; column 20,

line 21 - column 23, line 30; Figures 1,3,6,8,9,17-20.

TO

US 6848116 B1 (LAND THOMAS) 25.01.2005, column 1, line 15 - column 2, line 16; 1-10

column 2, line 66 - column 3, line 42; column 3, line 60 - column 6, line 32;

Figures 8-11H.

TO

US 5303229 A (WITHERS ANDREW L et al.) 12.04.1994, summary; figure 10. 1-5

TO

US 2007002870 A1 (PEKONEN HARRI J et al.) 04.01.2007, summary. 1-5

TO

WO 0225949 A2 (IBM et al.) 28.03.2002, summary; pages 5-7. 1-5

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 05.31.2011

Examiner J. Santaella Vallejo Page 1/5

REPORT OF THE STATE OF THE TECHNIQUE Minimum documentation sought (classification system followed by classification symbols) H04B, H04J Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC, WPI, Internet  WRITTEN OPINION Date of Completion of Written Opinion: 05.31.2011 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 1-10 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-10 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published.  WRITTEN OPINION 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 5790170 A (SUZUKI MITSUHIRO) 04.08.1998

D02

US 6848116 B1 (LAND THOMAS) 01.25.2005

D03

US 5303229 A (WITHERS ANDREW L et al.) 12.04.1994

D04

US 2007002870 A1 (PEKONEN HARRI J et al.) 04.01.2007

D05

WO 0225949 A2 (IBM et al.) 03/28/2002

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement In the claimed invention, an optical network terminal, an optical line terminal and a method for the diffusion of digital television content are presented to be able to separate the content into two streams and eliminate part of the content of one of the streams. The state of the art document closest to the invention is D01 discloses an optical network terminal, an optical line terminal for transmitting bi-directional information such as video signals on demand. For clarity, and as far as possible, the same wording used in claim 1 is used. The references in parentheses correspond to D01. Technical characteristics not found in document D01 are indicated in square brackets. Claim 1 Optical network terminal with at least one optical input / output port and a radio frequency output port (column 1, lines 36-46; column 8, lines 43-49; Figure 6) because it comprises means for:

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extracting, from a signal emitted by an optical line terminator equipment from a passive optical network and received through said optical input / output port (column 3, lines 8-32; figures 3C); a first radio frequency signal that carries a plurality of digital television channels (column 8, lines 43-49; column 9, line 46-column 10, line 26; figures 6, 8 and 9);

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performing, on said first radio frequency signal, a tunable selective filtering of digital television channels transported by said signal (column 8, lines 43-49; column 9, line 46-column 10, line 26; figures 6, 8 and 9) ;

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emitting from said radiofrequency output port a second radiofrequency signal carrying said filtered digital television channels (column 8, lines 43-49; column 9, line 46-column 10, line 26; figures 6, 8 and 9)

Where the means for carrying out said selective filtering comprise: a first tunable bandpass filter, configured to extract, from said first radio frequency signal, a plurality of radio frequency channels carrying transmission streams on which digital television channels are multiplexed broadcast to all users of the passive optical network (column 9, line 46-65; figure 9, elements 304,305);

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a second tunable pass-band filter, which operates in parallel to said first tunable pass-band filter, configured to extract, from said first radiofrequency signal, a radiofrequency channel that carries a transmission flow on which a channel is multiplexed digital television corresponding to a pay-per-view service requested by a user of said optical network terminal (column 9 line 66-column 10 line 26 figure 9 elements 307-309); control means for configuring said first tunable bandpass filter and said second tunable bandpass filter (column 11, lines 27-43; figure 8, element 320);

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a digital television receiver configured to demodulate a transmission stream from the radio frequency channel extracted by the second tunable band-pass filter (column 10, lines 16-25; column 23, lines 9-11; figure 9, element 310 and 311, figure 20 element 511)

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a demultiplexer configured to select, from a multiplexed digital television channels in said transmission stream demodulated by the digital television receiver, a digital television channel corresponding to a pay-per-view service requested by a user of said optical network terminal (column 10, lines 16-58, figure 8 element 317; figure 20, element 514);

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a multiplexer configured to generate a new transmission stream (column 10, lines 5-15; figure 8, item 317) from [the digital television channel selected by the demultiplexer, corresponding to the pay-per-view service requested by the user, and a filler content]; WRITTEN OPINION

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a modulator (column 10, lines 25-37; figure 9, element 312) [configured to modulate said new transmission flow in a radio frequency channel].

The difference between the D01 and the request is in the use made of the multiplexer and the modulator and the need to establish filler content. In D01 these elements (modulator and multiplexer) are used to establish a return channel with the video source in the header, instead in the invention it is used for once discarded the video channels to regenerate the signal. The technical effect of this difference is once the channels have been discarded, re-compose the signal, hence the need for “fill content” since the signal must be had in the same conditions as before demodulation. It is considered that a person skilled in the art would generate the signal again, since it composes it in the transmitter as seen in D01, regarding the introduction of a filler content it is a common practice of the state of the art to be able to maintain the synchronization . Therefore, in light of D01, the invention is new but lacks inventive activity as set forth in articles 6 and 8 of the 1986 Patent Law Claims 2-5 The use of attributes for configuration, said attributes being controlled by the optical line terminator through the control channel; The use of a microcontrolled NFC and the use of an improvement band is considered that in view of the aforementioned document D01, they are known to the person skilled in the art. Therefore in light of D01, inventions 2-5 are new but lack inventive activity as set forth in the Articles 6 and 8 of the 1986 Patent Law Claims 6 and 7 Optical line terminator comprising means for: -multiplex digital television channels in transmission streams; -modulate said transmission streams in radiofrequency channels; - emitting said modulated radio frequency channels in an optical signal through a passive optical network; -manage remotely tunable selective filtering of digital television channels that takes place in an optical terminal network connected to the optical line terminator through a passive optical network. Claims 6 and 7 are included in D01 column 1 lines 6-11; column 3, lines 57-64; column 20, line 20-column 22, line 2; Figures 4 and 19 Therefore, in light of D01, inventions 6 and 7 are new but lack inventive activity as set forth in articles 6 and 8 of the 1986 Patent Law Claims 8-10 The method for the transmission / reception of digital television channels, including digital rights management services. It is the method that implements the system composed of the optical network terminal and the optical line terminator described in claims 1-7 solving the same technical problem. Therefore, in light of D01, inventions 8-10 are new but lack inventive activity as set forth in articles 6 and 8 of the 1986 Patent Law