WO2004030362A1

WO2004030362A1 - A two-module digital television decoder

Info

Publication number: WO2004030362A1
Application number: PCT/PL2003/000093
Authority: WO
Inventors: Wiktor HODOWANY
Original assignee: Advanced Digital Broadcast Ltd.; Advanced Digital Broadcast Polska Sp. Z O.O.
Priority date: 2002-09-27
Filing date: 2003-09-22
Publication date: 2004-04-08
Also published as: PL356357A1; AU2003299062A8; AU2003299062A1

Abstract

The invention discloses a two-module digital television decoder, comprising two electronic circuit modules as an universal modem (1) and a decoding module (2) communicating with each other. The universal module (1) comprises a processor (CPU1) as a control component, means for controlling communication with the decoding module (2), comprising a multiplexer (MUX), a transceiver (TX1) and a wireless communication protocol controller, preferably implemented as a program in the processor (CPU1), and moreover it comprises a data bus (DB1) for transmitting signals received by the tuners (T1-T1n, T1-T2n) and a bus (CB1) for transmitting processor (CPU1) control commands. The decoding module (2) comprises means for controlling communication with the universal modem (1), comprising a transceiver (TX2), a signal filtering component in a form of a demultiplexer (DEMUX1) and a wireless communication protocol controller, preferably implemented as a program in the processor (CPU2), and means for processing the received signal, comprising the audio and video components (AP and VP) having the outputs (OA and OV), and it also comprises a conditional access component composed of a Smartcard controller (SC) and a descrambler (DS) and an audio/video decoding component composed of a demultiplexer (DEMUX2) of MPEG stream, splitting it into at least audio and video streams, an audio decoding component and a video decoding component (AD and VD), and a data bus (DB2) and a bus (CB2) for transmitting processor (CPU2) control commands.

Description

A two-module digital television decoder.

The object of the invention is a two-module digital television decoder, designed for reception of television signals broadcast by different operators.

The typical set-top boxes commonly used today comprise two main modules: a 'Front-End', which comprises signal receiving means and the 'Back-End', which comprises signal decoding and processing means.

Due to a large number of television signal broadcasters and different broadcasting methods (especially, methods related to coding), the decoders supplied to users are not universal from their point of view. A decoder adapted to reception of one broadcaster's signal, usually cannot process signals of other broadcasters.

The producers design decoders as ordered by television operators. The specifications given by operators differ, according to specific needs of each operator. Therefore, each new ordered model of a decoder differs at least in details from- previous models. This leads to high costs of production and a high price to be paid by the end user.

The differences between decoders, offered by various TN operators, involve mainly signal decoding procedures, which are executed by the Conditional Access (CA) unit.

A typical decoder structure, based on standard components, is presented in the international patent application WO0217638.

A similar solution is disclosed in the international patent application WOO 174079, which concerns a decoder comprising functional modules that communicate via a data bus. The Front-End module is a replaceable extension card, which constitutes an integral part of the decoder and is mounted inside it. Therefore, its replacement is possible only at the production stage or later by a qualified service. In the international patent application WO there is disclosed a system of two decoders, where one is a primary (master) and the other is a secondary (slave) decoder. However, the master decoder comprises also the features of the slave decoder, for example displaying video signal, which makes it a fully operational, standard decoder, but an expensive one. The presented solution is economic only for the users who use several television receivers. The master decoder is far more expensive than the slave decoder, which is why it is not preferred to use it as the only decoder in a household.

The US 6,040,851 patent discloses a small-format subsystem for control of broadband communication. It discloses an electronic communication system for a broadband network, comprising a separate, connectable DICAM digital subnetwork interface control module, configured for the reception of an RF audio/video signal and generation of a digital signal for error correction, and that module comprises a conditional access block and a Smartcard card reader. Since the conditional access block may perform operator-specific functions, the module is not universal and may have to be designed individually for each operator.

According to the present invention, in a two-module digital television decoder, comprising two electronic circuit modules communicating with each other, where the first module comprises components for reception of at least one satellite, terrestrial or cable television signal, which are at least one tuner and at least one demodulator, components providing communication with the second electronic circuit and a component controlling its operation, and the second module, designed for processing of the received digital television signal, comprises components providing communication with the first module and a component for control of a protocol used for communication with this circuit, a component for system control, data and graphics processing in a form of a processor, and audio/video components for converting the received signal to a format of an external receiver, the object of the invention is that the first module is a universal modem module and the second module is a decoding module, where the universal modem comprises a processor as a control component, means for controlling communication with the decoding module, comprising a multiplexer, a transceiver and a wireless communication protocol controller, preferably implemented as a program in the processor, and moreover it comprises a data bus for transmitting signals received by the tuners and a bus for transmitting processor control commands and the decoding module comprises means for controlling communication with the universal modem, comprising a transceiver, a signal filtering component in a form of a demultiplexer and a wireless communication protocol controller, preferably implemented as a program in the processor, and means for processing the received signal, comprising an audio component having an audio output and a video component having a video output and it also comprises a conditional access component composed of a Smartcard controller and a descrambler and an audio/video decoding component composed of a demultiplexer of MPEG stream, splitting it into at least audio and video streams, an audio decoding component and a video decoding component and a data bus and a bus for transmitting processor control commands.

Preferably, the modem module comprises additional components for transmission of data, connected to the transceiver via the data bus.

Preferably, the decoding module comprises components providing additional functionality to the user, connected to the processor.

Preferably, the data bus and processor control commands bus of the modem module are interconnected.

Preferably, the data bus and the processor control commands bus of the decoding module are interconnected.

According to another embodiment of the present invention, in a two-module digital television decoder, comprising two electronic circuit modules communicating with each other, where the first module comprises components for reception of at least one satellite, terrestrial or cable television signal, which are at least one tuner and at least one demodulator, components providing communication with the second electronic circuit and a component controlling its operation, and the second module, designed for processing of the received digital television signal, comprises components providing communication with the first module and a component for control of a protocol used for communication with this circuit, a component for system control, data and graphics processing in a form of a processor, and audio/video components for converting the received signal to a format of an external receiver, the object of the invention is that the first module is a universal modem module and the second module is a decoding module, where the universal modem comprises a processor as a control component, means for controlling commumcation with the decoding module, comprising a multi-channel multiplexer, a transceiver and a wireless communication protocol controller, preferably implemented as a program in the processor, and moreover it comprises individual data busses for transmitting signals received by individual tuners and a bus for transmitting processor control commands and the decoding module comprises means for controlling commumcation with the universal modem, comprising a multi-channel transceiver and a wireless commumcation protocol controller, preferably implemented as a program in the processor and means for processing the received signal, comprising an audio component having an audio output and a video component having a video output and it also comprises a conditional access component composed of a Smartcard controller and a descrambler and an audio/video decoding component composed of a demultiplexer of MPEG stream, splitting it into at least audio and video streams, an audio decoding component and a video decoding component and a data bus and a bus for transmitting processor control commands.

Preferably, in the above embodiment, the modem module comprises additional components for transmission of data, connected to the multi-channel transceiver via the data bus.

Preferably, the data busses and processor control commands bus of the modem module are interconnected.

According to yet another embodiment of the present invention, in a two-module digital television decoder, comprising two electronic circuit modules communicating with each other, where the first module comprises a component for reception of one satellite, terrestrial or cable television signal, which comprises at least a tuner and a demodulator, a component providing communication with the second electronic circuit and a component controlling its operation, and the second module, designed for processing of the received digital television signal, comprises components providing communication with the first module and a component for control of a protocol used for communication with this circuit, a component for system control, data and graphics processing in a form of a processor, and audio/video components for converting the received signal to a format of an external receiver, the object of the invention is that the first module is a universal modem module and the second module is a decoding module, where the universal modem comprises a processor as a control component, means for controlling communication with the decoding module, comprising a transceiver and a wireless communication protocol controller , preferably implemented as a progra in the processor, and moreover it comprises a data bus for transmitting signal received by the tuner and a control bus for transmitting processor control commands and the decoding module comprises means for controlling communication with the universal modem, comprising a transceiver and a wireless communication protocol controller, preferably implemented as a program in the processor and means for processing the received signal, comprising an audio component having an audio output and a video component having a video output and it also comprises a conditional access component composed of a Smartcard controller and a descrambler and an audio/video decoding component composed of a demultiplexer of MPEG stream, splitting it into at least audio and video streams, an audio decoding component and a video decoding component and a data bus and a bus for transmitting processor control commands.

The disclosed invention has several advantages, which result from the fact that the decoder comprises two distinct modules of specific functionality, which are connected wirelessly.

The wireless connection between the modem module and the decoding module makes their use exceptionally convenient.

The universal modem, designed for reception of television signal can be placed near the antenna socket that can be a cable TN, satellite or terrestrial antenna sockets.

The decoding module can be placed near the television receiver. It communicates with the universal modem via a broadband radio connection of a low power and range i.e. a few dozen meters, so that all household rooms can be covered without causing interference with other television signals of the neighboring users. The modem can be universal, i.e. one modem can receive television signals of different operators. In contrast, the decoding module is supplied to the user by a given operator and allows receiving of the television signal of that operator.

Therefore, the presented solution allows the reduction of manufacturing costs of the universal modem, since more units of one type can by manufactured and sold to several television operators.

Moreover, not taking into account cost of the radio connection, the cost of such a two-module decoder is similar to present standard integrated receiver decoders. Therefore, the disclosed invention has many advantages for both television operators and viewers.

The object of the invention is presented in exemplary embodiments explained in more details on a drawing, where fig. 1 shows the present invention on a simplified block diagram of both modules, fig. 2 presents a detailed block diagram of the universal modem, fig. 3 shows a detailed block diagram of a decoding module. Fig. 4 and fig. 5 present another embodiment of a modem and a decoding module accordingly. Fig. 6 shows the simplest embodiment of the universal modem, which can operate with the decoding module presented in fig. 5.

Fig. 1 presents a general scheme of communication between the universal modem ϋ and two decoding modules 13, 14, which clarifies the object of the invention.

The universal modem ϋ is connected to the source of a digital television signal. The signal is received by one or more tuners TJ,, T2 and then demodulated by demodulators Dl or D2 accordingly.

The output signals of the demodulators Dl, D2 are transmitted to a multiplexer MUX, which generates a uniform output stream OS .

The universal modem 11 also comprises a processor CPU receiving signals Si, S2 from the decoding modules 13, 14. The universal modem comprises also a radio transceiver TX for sending and receiving signals.

The decoding module comprises also a transceiver TX, connected with the demultiplexer DEMUX that passes appropriate signals to the data processing processor CPU. The converted signals are displayed on the screens of television receivers TNI, TN2 respectively. The universal modem H transmits its signal via the main broadband channel. The signals generated by both decoding modules 13, 14 can be transmitted via a return channel of a lower bandwidth, enough for sending simple control commands.

The communication standard that should be employed for transmission of data between the universal modem H and the decoding modules 13, 14 must be efficient enough to transmit all data generated by the modem.

The link is mainly used by the universal modem H, which transmits a data stream that can require a bandwidth from several up to few dozens of megabits per second. The decoding modules 13, 14 transmit to the universal modem H only control commands, which do not require a broad band.

The connection must be supplied for the distance not less than the distance between the universal modem ϋ and the decoding modules 13, 14. Usually, it is not grater than a few dozens of meters.

The communication protocol must provide an adequate level of security, so that only one or more addressed decoding modules could receive the signal generated by the universal modem.

Exemplary protocols that meet the above requirements are the IEEE 802.11 or the HiperLAN protocols.

Each decoding module transmits tuner control commands to the universal modem. For example, such commands control a return channel of a cable television in the DOCSIS standard or a PSTN modem. Moreover, the decoding module can also send data to be transmitted.

The two-module digital television decoder according to the invention comprises two modules communicating with each other, from which the first is the universal modem module and the second is the decoding module.

The structure of first embodiment of the modem module 1 is shown in Fig. 2. It comprises components for receiving at least one satellite, terrestrial or cable television signal. In Fig. 2, two data receiving blocks are presented, comprising tuners TJ, ... Tin and T2 ... T2n and corresponding demodulators

Dl ... Din and D2 ... D2n, which allow reception of two different input signals. The universal modem 1 additionally comprises a CPUl processor for control of its operation and communication means, comprising a multiplexer MUX, a transceiver TX1 and a wireless transmission controller, preferably implemented as a program in the processor CPUl. The modem also comprises a bus for transmitting signals received by the tuners Tl ... Tin and T2 ... T2n that is a data bus DB1 and a bus for transmitting processor control commands that is a bus CB1.

The first embodiment of the decoding module 2 is shown in Fig. 3. It comprises a transceiver TX2 for communication with the universal modem I, a component for filtering signals received from the modem module 1, in a form of a demultiplexer DEMUXl and a wireless transmission controller, preferably implemented as a program in the processor CPU2. The decoding module 2 also comprises signal processing components, for processing audio AP (having an audio output OA) and video NP (having a video output ON). Moreover, it comprises a conditional access means comprising a Smartcards SC controller, a descrambler DS and an audio/video decoding means comprising a demultiplexer DEMUX2 that splits an MPEG stream into at least audio and video streams, a video decoding component ND and an audio decoding component AD. Additionally, the decoder 2 comprises a data bus DB2 and processor CPU2 control commands bus CB2.

The universal modem 1 in this embodiment can comprise an additional component DTR for data transmission, connected to the data bus DB1. The DTR component may provide connection to Internet, for example through an xDSL line, a cable modem, a telephone modem or other means for receiving external signals that may be processed by the decoder.

Similarly, the decoding module 2 can comprise a block of additional user- functions components UFB. connected to the processor CPU2- for executing user- defined actions. The additional components may perform functions related to a remote control unit, DNR (Digital Video Recording), Time-Shifted Interactive TV or T- commerce.

The data bus DB1 and the control bus CB1 of the universal modem 1 may be interconnected.

Similarly, the data bus DB2 and the control bus CB2 of the decoding module 2 may also be interconnected. According to a second embodiment of the present invention, another data transmission method can be applied between the universal modem module and the decoding module.

Instead of sending a multiplexed stream of signals from several tuners by one radio channel, which requires a multiplexer and a wireless connection of a broad bandwidth, the streams may be transmitted using separate channels. In such a case, several channels of smaller capacity replace one broadband channel.

A configuration of a modem 10 and a decoding module 20 which utilizes a transmission scheme described above is shown in Fig. 4 and Fig. 5 respectively.

The universal modem 10 shown in Fig. 4 is identical to the modem shown in Fig. 2 except that it does not comprise a multiplexer MUX and its transceiver is a multichannel transceiver TX10. The signals from the outputs of the demodulators and other components are sent directly to the transceiver TX10 via the data busses DB10 - DB14.

The decoding module 20 shown in Fig. 5 is identical to the decoding module shown in Fig. 3 except that it does not comprise a demultiplexer DEMUXl between the transceiver TX20 and the descrambler DS, which are now directly connected. The transceiver is a multi-channel transceiver TX20.

The processor CPU2 controls the transceiver TX20 so that it receives data from an appropriate channel.

The remaining components of the modules are the same so their identifying labels in the drawings are left unchanged.

Also in this embodiment the data busses DB10 - DB14 and the control commands bus CB10 in the universal modem module 10 can be interconnected.

Similarly, the data bus DB20 and the control bus CB20 of the decoding module 20 may also be interconnected.

The third, the simplest embodiment of the universal modem 100 is shown in Fig. 6. It can operate with the decoding module shown in Fig. 5.

In this embodiment, the universal modem 100 comprises only one tuner T100, one demodulator D100. a processor CPUl 00 controlling the modem and a transceiver TXIOO. In this case, the transceiver TXIOO controls only one main channel and a return channel. Also in this embodiment the data bus DB100 and the control commands bus CB100 in the universal modem module 100 can be interconnected.

There is also possible an embodiment where the universal modem 100 signal is received by several decoding modules.

The only limitation is that all decoding modules receive the same television signal.

Claims

1. A two-module digital television decoder, comprising two electronic circuit modules communicating with each other, where the first module comprises components for reception of at least one satellite, terrestrial or cable television signal, which are at least one tuner and at least one demodulator, components providing communication with the second electronic circuit and a component controlling its operation, and the second module, designed for processing of the received digital television signal, comprises components providing communication with the first module and a component for control of a protocol used for communication with this circuit, a component for system control, data and graphics processing in a form of a processor, and audio/video components for converting the received signal to a format of an external receiver, characterized in that the first module is a universal modem module 1 and the second module is a decoding module 2, where the universal modem 1 comprises a processor CPUl as a control component, means for controlling communication with the decoding module 2, comprising a multiplexer MUX, a transceiver TX1 and a wireless communication protocol controller, preferably implemented as a program in the processor CPUl. and moreover it comprises a data bus DB1 for transmitting signals received by the tuners Tl-Tln. T2-T2n and a bus CB1 for transmitting processor CPUl control commands and the decoding module 2 comprises means for controlling communication with the universal modem 1 comprising a transceiver TX2, a signal filtering component in a form of a demultiplexer DEMUXl and a wireless communication protocol controller, preferably implemented as a program in the processor CPU2. and means for processing the received signal, comprising the audio and video components AP and NP having the outputs suitably OA and ON, it also comprises a conditional access component, composed of a Smartcard controller SC and a descrambler DS and an audio/video decoding component, composed of a demultiplexer DEMUX2 of MPEG stream, splitting it into at least audio and video streams, an audio decoding component AD and a video decoding component ND and a data bus DB2 and a bus CB2 for transmitting processor CPU2 control commands.

2. A two-module digital television decoder according to the claim 1, characterized in that the modem module 1 comprises additional components DTR, for transmission of data, connected to the transceiver TX1 via the data bus DBl.

3. A two-module digital television decoder according to the claim 1, characterized in that the decoding module 2 comprises components UFB providing additional functionality to the user, connected to the processor CPU2.

4. A two-module digital television decoder according to the claim 1, characterized in that the data bus DBl and processor control commands bus CBl of the modem module 1 are interconnected.

5. A two-module digital television decoder according to the claim 1 or 2 or 3, characterized in that the data bus DB2 and processor control commands bus CB2 of the modem module 2 are interconnected.

6. A two-module digital television decoder according to the claim 1 or 2 or 3, characterized in that the data bus DBl and processor control commands bus CBl of the modem module 1 are interconnected and the data bus DB2 and processor control commands bus CB2 of the modem module 2 are interconnected as well.

7. A two-module digital television decoder, comprising two electronic circuit modules communicating with each other, where the first module comprises components for reception of at least one satellite, terrestrial or cable television signal, which are at least one tuner and at least one demodulator, components providing communication with the second electronic circuit and a component controlling its operation, and the second module, designed for processing of the received digital television signal, comprises components providing communication with the first module and a component for control of a protocol used for communication with this circuit, a component for system control, data and graphics processing in a form of a processor, and audio/video components for converting the received signal to a format of an external receiver, characterized in that the first module is a universal modem module 10 and the second module is a decoding module 20, where the universal modem module 10 comprises a processor CPUl as a control component, means for controlling communication with the decoding module 20, comprising a multi-channel transceiver TX10 and a wireless communication protocol controller, preferably implemented as a program in the processor CPUl. and moreover it comprises individual data busses DB10-DB14 for transmitting signals received by individual tuners Tl-Tln. T2-T2n and a bus CB10 for transmitting processor CPUl control commands and the decoding module 20 comprises means for controlling communication with the universal modem 10, comprising a multichannel transceiver TX20 and a wireless communication protocol controller, preferably implemented as a program in the processor CPU2 and means for processing the received signal, comprising the audio and components AP and NP having the outputs suitably OA and ON, it also comprises a conditional access component composed of a Smartcard controller SC and a descrambler DS and an audio/video decoding component composed of a demultiplexer DEMUX2 of MPEG stream, splitting it into at least audio and video streams, the audio and a video decoding components AD and ND. and a data bus DB20 and a bus CB20 for transmitting processor CPU2 control commands.

8. A two-module digital television decoder according to the claim 7, characterized in that the modem module 10 comprises additional components DTR for transmission of data, connected to the transceiver TX10 via the data bus DBl 4.

9. A two-module digital television decoder according to the claim 7, characterized in that the decoding module 20 comprises components UFB providing additional functionality to the user, connected to the processor CPU2.

10. A two-module digital television decoder according to the claim 7 or 8 or 9, characterized in that the data busses DB10-DB14 and processor control commands bus CB10 of the modem module 10 are interconnected.

11. A two-module digital television decoder according to the claim 7 or 8 or 9, characterized in that the data bus DB20 and processor control commands bus CB20 of the modem module 20 are interconnected.

12. A two-module digital television decoder according to the claim 7 or 8 or 9, characterized in that the data busses DB10-DB14 and processor control commands bus CB10 of the modem module 10 are interconnected and the data bus DB20 and processor control commands bus CB20 of the modem module 20 are interconnected as well.

13. A two-module digital television decoder, comprising two electronic circuit modules communicating with each other, where the first module comprises components for reception of at least one satellite, terrestrial or cable television signal, which are at least one tuner and at least one demodulator, components providing communication with the second electronic circuit and a component controlling its operation, and the second module, designed for processing of the received digital television signal, comprises components providing communication with the first module and a component for control of a protocol used for communication with this circuit, a component for system control, data and graphics processing in a form of a processor, and audio/video components for converting the received signal to a format of an external receiver, characterized in that the first module is a universal modem module 100 and the second module is a decoding module 20, where the universal modem module 100 comprises a processor CPUl 00 as a control component, means for controlling communication with the decoding module 20, comprising a transceiver TX100 and a wireless communication protocol controller , preferably implemented as a program in the processor CPUl 00. and moreover it comprises a data bus DBl 00 for transmitting signal received by the tuner T100 with a demodulator D100 and a control bus CBl 00 for transmitting processor CPUl 00 control commands, and the decoding module 20 comprises means for controlling communication with the universal modem 100. comprising a transceiver TX20 and a wireless communication protocol controller, preferably implemented as a program in the processor CPU2 and means for processing the received signal, comprising the audio and video components AP and NP having the outputs suitably OA and ON and it also comprises a conditional access component composed of a Smartcard controller SC and a descrambler DS and an audio/video decoding component composed of a demultiplexer DEMUX2 of MPEG stream, splitting it into at least audio and video streams, the audio and video decoding components AD and ND and the data busses DB20 and CB20 for transmitting processor CPU2 control commands.

14. A two-module digital television decoder according to the claim 13, characterized in that the modem module 20 comprises additional components UFB for transmission of data, connected to the transceiver TX20 via the data bus DB20.

15. A two-module digital television decoder according to the claim 13 or 14, characterized in that the data bus DBl 00 and processor control commands bus CBl 00 of the modem module 100 are interconnected.

16. A two-module digital television decoder according to the claim 13 or 14, characterized in that the data bus DB20 and processor control commands bus CB20 of the modem module 20 are interconnected.

17. A two-module digital television decoder according to the claim 13 or 14, characterized in that the data bus DBl 00 and processor control commands bus CBl 00 of the modem module 100 are interconnected and the data bus DB20 and processor control commands bus CB20 of the modem module 20 are interconnected as well.