DEVICE FOR ACCESSING CABLE DISTRIBUTION TELEVISION SIGNALS

Abstract: The present invention relates to a Device for accessing to CATV distribution signals, making part of a distribution system of CATV signal, which comprises one head end (4), a distribution network (1), local points of access (6), a plug (9) and a TV set receptor. The said device comprises reading and control means (2), pre-paid validation means recognized by CATV network operators, and filter means (3), the reading and control means (2) making the reading of the pre-paid validation means recognized by the CATV operators (10), the recognition of the pre-paid validation means recognized by CATV network operators (10) and the discount of the credits (impulses) and the sending of commands to those filter means (3) that make a security recognition of commands and send the CATV signal to the TV set, this being made according to the features of the pre-paid validation means recognized by the CATV network operators (10) and because the communications for access control of the signal distributed through the CATV network (1) are limited to the connection between the reading and control means (2) and the filter means (3).

Description: "Device for accessing to Cable Distribution Television Signals" The present invention relates to a device for accessing to cable television (CATV) distribution signal, used in CATV distribution networks. Currently, several products and services are commercialized throughout the signal distributed by cable. Such means that it is necessary the pre- installation on a building with cabling and respective equipment to make available the signal distributed by cable. That is due to the bandwidth distributed by the cable cannot be available in a partial or complete and commuted way by the user direct local control. As a consequence of this, if the potential user doesn't subscribe the CATV service, the operator without any guarantee of amortization will support the costs of pre-installation. For the users subscribing a minimum or limited service, the operator must to install in the building in question, a "band-pass" filter, that just blocks up a frequency range in a fixed way and which installation and removal are made by a technician that has to go to the local. According to a recent study, made during 1 999, in the EU, the average penetration rate in the CATV market is only 28% which means that just a small part of the infrastructure makes the amortization of the investment made. So it becomes necessary the profitability of the investment made in the distribution infrastructure. There is according the necessity of a device that overcomes previously referred inconveniences. One of the main goals of the present invention is to proportionate such device. Attending to the big discrepancy between the cabled homes and the number of subscribers, the present invention provides a device to give an answer to the difficulties felt by the operators. The device of the present invention makes possible the access or the suspension of the access to the CATV signal distribution, controlled locally by the user, through validation means recognized by the CATV operators with an associated minimum cost, giving flexibility and autonomy. Once that the device of the present invention uses the cabling already existent, the same allows to rise up the investment already made in infrastructures. It is wanted that the CATV operators consider the pre-installation of this equipment in all the cabled homes, once the additional cost is compatible with initial investment. Therefore, the device of the present invention allows to each CATV network user, the autonomous and anonymous control of access to the available signal in the local network, with very low costs, through the validation means recognized by the CATV operators. The implementation problem of a low cost device results from the necessity to transmit to the operator the access requests from each user. This due to all communications (from the user to the operator) have to be synchronized and controlled by equipment having high costs and complex installation, which became unnecessary with the present device. Further the present invention provides great economies in what relates to the billing costs and costs due to non-payment, those are aspects that have more and more importance in the general exploitation costs. According to the invention, the bi-directional command communications and the validation between the reading and control means, and the filter means are implemented using in the direction from the first to the second one, the modulation of the impulse width (data transmission). And, in the direction from the filter means to the reading and control means, the variation of the power consumption of the filter means. This way, the instructions of command and validation are sent through the reading and control means that control the filter means that permit to limit/ access to a frequency range that the same ones allow. The reading and control means can be activated by the user through pre-paid validation means recognized by the operators of the CATV network. The validation means can consist in a button, a PC, an intelligent card (chip card), a Dallas chip, in a fingerprint reader or in any other way of direct and protected command and send commands to the filter means. For its turn, the filter means are conceived in a way to block up every frequency in the signal of cable in the absence of encoded commands (or to allow the passage of just a few frequencies that form a basic service). And when receiving valid encoded commands they make available the other frequencies that define the new service according to the features of validation means, recognized by the CATV operators. To solve this problem, maintaining the maximum user's autonomy and anonymity, it is preferred to consume the pre-paid validation means recognized by the CATV operators (for example the pre-paid cards) at user's homes, instead of transmitting the access requests to operators. The transfer of the control of access to the reading and control means, driven by the pre-paid validation means recognized by the CATV operators, it is necessary that said reading means debit impulses into said pre-paid means and convert the same ones in time of usage of the CATV signal. By commanding those reading and control means and filter means, that are introduced in the final portion of CATV distribution network, but out of user's access. This solution maintains the necessity of communications in the direction from the user to the operator but, once that these ones are restricted to the portion between the reading and control means and the filter means, don't need synchronism or control through high-cost equipment or of complex technical installation. The device according to the invention comprises reading and control means, pre-paid validation means, recognized by the CATV network operators, and filter means. The reading and control means make the reading of the pre-paid validation means, recognized by the CATV network operators, the credit discount and the recognition of the said pre-paid validation means, send commands to the filter means. These make the security recognition of commands and send the CATV signal to the TV set, according to the features of the pre-paid validation means recognized by the CATV operators. The filter means are conceived in a way to block up the totality of the CATV signal, or to allow the passage of some signal frequencies that constitutes a basic service, in the absence of commands from those reading and control means. And in the presence of such commands to release a part of the CATV signal or the totality of the same one, according to the features of the said pre-paid validation means, recognized by the CATV network operators. The device of the present invention conjugates the filter means with the reading and control means, activated by the pre-paid validation means, recognized by the CATV network operators to proportionate the access to CATV signal. Being created a new concept of "paying to see" and enlarging the number of options, that allows to each client to choose the package of channels most adequate to their needs. This way, it's possible the availability of the pre-paid validation means recognized by the CATV network operators with a signature to just one channel or to a package of encoded channels. These, can be even common to different operators, pre-paid validation means whose credit units change according to the channels, or special pre-paid validation means that allow the monthly access to all encoded channels. The invention will now be described with base in an example represented in the figures, in which: Figure 1 is a block diagram of a CATV signal distribution system that includes a device according the present invention; Figure 2 is a block diagram of a card reader and control unit used in the device according to the invention; and Figure 3 is a block diagram of a filter unit used in the device according to the invention. In the embodiment represented in figure 1 , the card reader and control unit 2 embodies the reading and control means and the filter unit 3 embodies the filter means. The pre-paid validation means recognized by the CATV network operators are embodied by the pre-paid chip card 1 0. The distribution system of CATV signal distribution represented in figure 1 , includes besides the invention's device, a distribution network 1 , the cable's head end 4, the points of local access 6, a plug 9 from the user's home and the power mains 1 1 . In the system of CATV signal distribution represented in figure 1 , the head end 4 is connected through the main distribution network to the local points of access 6, being each one of those connected through a filter unit 3 to a plug 9 of user's home. This one is connected to a card reader and control unit 2, this one being connected to the input of the antenna's TV set and being fed by the public mains 1 1 . The system represented in figure 1 operates in the following way, the signal of CATV is distributed through the network 1 to the local points of access 6. From those, the signal of CATV passes to the filter unit 3, where some of the frequencies that are usually available through a TV antenna, are left to pass by. Or further are left to pass by only a few frequencies that compose the CATV signal or the entire range of frequencies. The signal coming from the filter unit 3 passes through the plug 9 to the card reader and control unit 2 and from there to the TV set. The card reader and control unit 2 is power fed through the public mains 1 1 . The filter unit 3 is a passive unit that receives the power from the card reader and control unit 2. The card reader and control unit 2, represented in figure 2 includes a card interface 21 , which makes the functions of electrical protection to the microcontroller pins, impedance adaptation and consumption detection of the pre-paid card 1 0. This is an essential feature for the device's reliability, because these pins are exposed to the aggression of an outsider element, such as the chip card, which can carry great electromagnetic interference. Said feature allows the microcontroller 22 to do the reading and its recognition and the diminution of the credit units contained in the same one. Once the microcontroller 22 has made these operations, it commands an impulse width modulator (PWM) 23, that sends a command, through signal modulation in impulse width of the power supply, to the filter unit 3 (shown in figure 3) . The filter unit 3 answers by changing its consumption with an asynchronous bit stream. Once that the communications are added to their own transmitted signal it was introduced a harmonics filter 24 and a DC decoupling device 26 of the continuos electrical energy component, in a way to prevent eventual interference in the CATV signal. Upstream the harmonics filter 24 is connected a consumption detector 25 whose function is, during the recognition of the pre-paid card 10, to check the existence of a filter unit 3. If the verification of the filter unit 3 is positive, the consumption detector authorizes that the microcontroller makes the credit discount (impulse) in the pre-paid card 1 0. Due to the applications diversity of this device can be included some products with indexed rate to a weekly day or month. For that reason was included in the device the watch 27 (watch/calendar) and the oscillator 28, and the backup battery 29, that allow the continuos and autonomous operation of the watch 27. The watch 27 also allows rising up the security levels, through the introduction of validity limits in the pre-paid cards 1 0. The microcontroller 22 also has a non-volatile memory that registers the functioning historical that determinates the permanent evolution of codification, being necessary to use evolutive codification to achieve acceptable security levels. The filter unit 3, represented in figure 3, is intended to control the access of the user to the available band in the cable, commuting between the availability of the entire band and the restriction of a small part of the same one. The filter unit 3 comprises a pass-band filter 31 , which limits the pass- band to the frequencies defined as free usage and presents an high attenuation in all other frequencies, not allowing any non authorized frequency to pass to the user. The filter unit 3 also comprises a microprocessor 33, a communication encoder 34 and an impulse width demodulator 35. The said filter unit 3 receives the activation commands and processes by software the decoding, time control and drive functions of the coaxial commuter 32, which activates the selection of the available frequencies, between the limited band by the filter and the total pass-band. This filter unit 3 also has a supply voltage regulator 36 to compensate eventual losses of voltage transmission line between the card reader and control unit 2 and the filter unit 3. The filter unit 3 also has a DC decoupling component 37, in order that the DC component doesn't pass from the cable TV distribution network to the filter unit. The combination of the filter 31 and the coaxial commuter 32 permits, in the frequency spectrum available in the distribution infrastructure of CATV signal, to limit in a selective and commuted way, the access to some frequencies. Its operation is dependent on the commands from the card reader and control unit 2, as indicated before, and on the validation of the valid pre- paid card 1 0. The command and validation bi-directional communications between the reading and control unit and the filter unit are implemented in the direction of the card reader and control unit 2 to the filter unit 3 by using the impulse width modulator 23 (data transmission) and in the direction of the filter unit 3 to the card reader and control unit 2 by using the variation the power consumption of the filter unit 3 that is detected by the consumption detector 25. The insertion of a valid pre-paid card 1 0 in the card interface has as consequence the emission by the microcontroller 22 of an encoded signal through a security complex mathematics algorithm to the filter unit 3. The encoded signal is interpreted by the microprocessor 33 and by the associated communication encoder 34, from the filter unit 3 and is used to check if there is effectively a pre-paid card in the card interface 21 . After such verification and upon reception the command from the impulse width modulator, the filter unit 3 sends the CATV signal according to the features of the pre-paid card 10 to the TV set. The signal, coming from the filter unit 3 is uncoupled from DC through the uncoupling organ DC 26 in a way that the component DC doesn't pass to the CATV distribution network. The potentialities of the described device allow to improve the offer of products adequate to clients needs, maximizing the usage of CATV network infrastructure 1 and the promotion of the operator's image. These advantages associated with some of the features device, as the effective control of the available time and the management capacity of different usage rates according to the channel; allow a unique way of promotion and commercialization of this kind of service. Thus, and independently from both restrictions format and command given by the card reader and control unit 2, the filter unit 3 makes possible the following functions: Access to a limited range of frequencies without the authorization from the card reader and control unit 2, giving access to some channels and services without using the pre-paid card 10; or Availability without restrictions to the entire frequency spectrum upon the insertion of a valid pre-paid card 10 in the card reader and control unit 2; or Acceptance of time management commands of the card reader and control unit being enough for a session to be concluded that the card reader stops sending this information. The filter unit 3, due to its small dimensions, is compatible with most of the TAPs used in CATV signal distribution; this unit has an easy installation having similar features to the pass-band filters. If the access to the CATV signal is protected (conditioned to a certain type of payment), the use of a card allows the access to a wider range of frequencies than the one that is initially available. That access is made through a credit discount (impulses) with correspondent time units that the pre-paid card 1 0 has. There are many applications associated to the device according to the invention. This one, besides its accessible price, that permits it usage in the entire CATV distribution infrastructure, it also allows the creation of new products and services with base in the sale and promotion of pre-paid cards, among them are pointed out: - The distribution and sale of pre-paid cards with hours or days of access to the CATV signal. - The promotion of pre-paid cards for accessing in a determined month or for limited use on weekends, and pre-paid cards of monthly subscription that can reduce the costs of exploitation. - The use of pre-paid cards as a vehicle of publicity to other entities. - The promotion of the cards in magazines editions and other kinds of media. - The offer of the pre-paid card to promote the operator. - The promotion of the pre-paid card as a collection item. All these advantages, associated to some features of the device, as the effective control of the available time and the management capacity of the different usage rates according to the channel, allow a unique form of promotion and commercialization of this kind of service. It is obvious that is possible many different modifications and variations of the present invention. Therefor it must be understood that in the scope of the attached claims, the device can be put in practice in a different ways than the one described here.

Claims: Claims 1 - Device for accessing to CATV distribution signals, to take part of a CATV signal distribution system, which comprises a network head end (4), a distribution network (1 ), local access points (6), a plug (9) and a TV set, characterized in that said access device comprises reading and control means (2), pre-paid validation means recognized by the CATV network operators (1 0), and filter means (3), the reading and control means (2) making the reading of the prepaid validation means recognized by the CATV network operators (1 0), the recognition of the pre-paid validation means recognized by the CATV network operators (1 0) and the discount of the credits (impulses) and the sending of commands to those filter means (3) that make a security recognition of commands and send the CATV signal to the TV set, this being made according to the features of the pre-paid validation means recognized by the CATV network operators (1 0) and because the communications for access control of the signal distributed through the CATV network (1 ) are limited to the connection between the reading and control means (2) and the filter means (3) . 2 - Device for accessing to CATV distribution signals according to claim 1 , characterized in that the command and validation bi-directional communications between the reading and control means (2) and the filter means (3) are implemented in the direction of the reading and control means (2) to the filter means (3) by using the impulse width modulation (23) (data transmission) and in the direction of the filter means (3) to the reading and control means (2), by using the variation of power consumption of the filter means (3) that is detected (25) by the reading and control means (2) . 3 - Device for accessing to CATV distribution signals according to the claims 1 and 2, characterized in that the reading and control means (2) have a card interface (21 ), a microcontroller (22), an impulse width modulator (23), an harmonics filter (24), a decoupling component DC (26), a consumption detector (25), a real time watch (27), an oscillator (28) and a backup battery (29) . 4 - Device for accessing to CATV distribution signals according to the claim 3, characterized in that the microcontroller (22) has a non-volatile memory that registers the operating historic, that determinate the permanent evolution of the signal encoding sent to the filter means (3) . 5 - Device for accessing to CATV distribution signals according to the claims 1 and 2, characterized in that the filter means (3) have a pass-band filter (31 ), a microprocessor (33), a communication encoder (34), an impulse width modulator (35), a coaxial commuter (32), supply voltage regulator (36) and a decoupling component DC (37) .

Inventors: CALHEIROS LEONEL JORGE SILVA G, CALHEIROS, LEONEL, JORGE, SILVA, GIRAO
Applicants: CALHEIROS LEONEL JORGE SILVA G, TECH4CABLE INC, CALHEIROS, LEONEL, JORGE, SILVA, GIRAO, TECH4CABLE INC.
Application year: 2001
Main classification: H04N7
IPC codes: H04N7