KR100988261B1 - Conditional Access System of Transport Stream and method thereof - Google Patents

Abstract

The conditional access method of a digital broadcast signal according to the present invention is a conditional access method of a digital broadcast receiver that decrypts a digital broadcast signal (TS) encrypted and transmitted, and includes specific information from a conditional access module (CAM) connected to a common interface module. Extracting; Identifying a type of CAM corresponding to the specific information by referring to a CAM information table previously stored in a memory; And decoding the digital broadcast signal by executing one or more programs corresponding to the type of CAM.

According to the present invention, by extracting certain information from the predetermined CAM inserted into the PCMCIA of the CI module and delivers it to the CI control unit, the CI control unit to support the CAM inserted through the normal operation, more efficient There is an advantage that conditional access of the digital broadcast signal is possible.

Description

Conditional access system and method thereof for digital broadcast signal

1 is a block diagram schematically showing a conditional access system of a digital broadcast signal according to the present invention;

2 is a method showing a conditional access method of a digital broadcast signal according to the present invention.

<Explanation of symbols for the main parts of the drawings>

12: CI control unit 13: CI module (PCMCIA)

14: CAM 17: CPU18: Memory

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conditional access system for a digital broadcast signal and a method thereof, and in particular, extracts specific information from a predetermined conditional access module in which a common interface control unit is inserted into a PCMCIA. The present invention relates to a conditional access system of a digital broadcast signal and a method for supporting normal operation of the inserted conditional access module.                         

Digital broadcasting is gradually being activated due to the commercial advantage of using a digital technology to broadcast a much wider variety of channels, and various functions such as high image quality, sound, interactive service, and internet access.

Accordingly, the digital set-top box industry is growing mainly in the US and Europe, and is showing high growth in the Middle East and Asia due to the introduction of the digital broadcasting.

The digital broadcasting is mainly led by pay broadcasting companies, and the direct purchase of pay broadcasting business is a big part of the set top box market. In terms of technology, digital set-top boxes are used to code analog content on the broadcasting station to digitize the broadcast signal so that customers can watch it on a regular TV through satellite or cable ground. .

However, since the above process requires complicated processing, a technical problem has been raised for broadcasters to supply various broadcasting services.

This is a matter of broadcasting standards, and the standards currently adopted by most broadcasters in the world are the European standard called DVB (Digital Video Broadcasting) or DSS (Digital Satellite Service) in the US. Various criteria are defined, such as the adoption of its own criteria.

In addition, a technology called a Conditional Access System (CAS) that restricts reception so that only subscribers can receive in pay broadcasting, that is, conditionally access the digital satellite broadcasting signal (TS) More than 10 companies are competing, including Media-Guard, NDS, and Viaccess.

Such CAS refers to a conditional access device of a set-top box for digital satellite broadcasting, and is responsible for a paid reception function of digital satellite broadcasting.

In this case, in order to transmit and receive only a specific TS, that is, to protect the digital broadcasting content, the MPEG packets should be scrambled and transmitted for the specific TS, and then descrambled by the receiver so that the viewer can view the broadcasting content. do.

This decryption is accomplished through a conditional access module (CAM) in the form of a card that plugs into the PCMCIA slot, which is then encrypted via a common interface (CI) module and initially encrypted. The decoded content is then decoded, and finally the transmitted broadcasting content is displayed to the user through a demultiplexer, an MPEG decoder, or the like.

However, in the digital satellite broadcasting having multiple channels, the CAMs that decode the TS for each channel have different software depending on the company that manufactures the corresponding CAM. The implementation of the CI module to be connected becomes difficult.

That is, when using a variety of CAM as in the conventional case, there is a disadvantage that it is difficult to implement a CI module that supports each such CAM to operate normally, accordingly the TS that receives a predetermined CAM connected to the CI is received. Sometimes problems arise that can't be decrypted normally.

The present invention stores a list of the specific information of the various CAMs connected to the CI module in the CI control unit, extracts certain information from the predetermined CAM inserted into the PCMCIA of the CI module and transfers it to the CI control unit, the insertion It is an object of the present invention to provide a conditional access system and method for digital broadcast signal supporting normal operation of a CAM.

A conditional access system of a digital broadcast signal according to the present invention for achieving the above object is a conditional access system of a digital broadcast receiver that decrypts a digital broadcast signal (TS) that is encrypted and transmitted. Conditional access module (CAM); A common interface (CI) module coupled to the CAM and extracting specific information from the CAM; A memory in which a CAM information table capable of identifying the type of CAM holding the specific information is stored in advance; And a common interface (CI) control unit configured to decode the digital broadcast signal by executing each program corresponding to the type of the corresponding CAM based on the information stored in the memory.

The method may further include a CPU configured to identify a type of the corresponding CAM by using the CAM information table stored in the memory and transmit the same to the common interface (CI) controller.

In addition, the CAM can decode only an encrypted signal corresponding to a predetermined channel among digital broadcast signals of various channels, and the specific information can be applied to an application_manufacturer and a manufacturer_code for the CAM. manufacturer _ code).

In addition, the conditional access method of the digital broadcast receiver according to the present invention for achieving the above object, the conditional access method of the digital broadcast receiver for decrypting the digital broadcast signal (TS) transmitted encrypted, the conditional unit connected to the common interface module Extracting specific information from an access module (CAM); Identifying a type of CAM corresponding to the specific information by referring to a CAM information table previously stored in a memory; And decoding the digital broadcast signal by executing one or more programs corresponding to the type of CAM.

In this case, the execution of one or more programs corresponding to the type of the CAM is performed by reading a program list associated with the type of the CAM and executing the programs corresponding to the list of each step. It consists of individual programs.

According to the present invention, by extracting certain information from the predetermined CAM inserted into the PCMCIA of the CI module and delivers it to the CI control unit, the CI control unit to support the CAM inserted through the normal operation, more efficient There is an advantage that conditional access of the digital broadcast signal is possible.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically illustrating a conditional access system of a digital broadcast signal according to the present invention.

Referring to FIG. 1, this is a tuner 10 for frequency tuning a received digital broadcast signal (TS) and a broadcast stream initially transmitted by demodulating the TS tuned by the tuner 10. The demodulator 11 which detects a signal is provided. However, the received TS is encrypted in a predetermined manner, and the TS passing through the tuner 10 and the demodulator 11 is also maintained in an encrypted state.

As such, the TS that has passed through the tuner 10 and the demodulator 11 has a common interface (CI) control unit 12, a CI module and PCMCIA 13, and a conditional access module (CAM). Descrambling via (14), followed by demultiplexer (DEMUX) 15, which is then synthesized into a single channel in the multiplexer (MUX) of the original broadcast station, and also separated by the demultiplexer 15. The decompressed TS is decompressed by the MPEG decoder 16 so that the TS, that is, the broadcast content that is first transmitted first, is displayed to the user.

At this time, the CAM 14 serves to decrypt the encrypted TS, and this CAM 14 is connected to the PCMCIA 13 slot of the CI module, and the CI control unit 12 is connected to the CI module. It controls the operation of (13).

However, the digital broadcasting is provided with various broadcasting contents through multiple channels. In this case, in the digital satellite broadcasting having multiple channels, CAMs that decode TSs for the respective channels are determined according to the manufacturing company. The software SW is distinguished. That is, each CAM can decrypt only the encrypted TS corresponding to a specific channel among TSs of various channels.

Accordingly, in the conventional case, in the CI module to be connected to the various CAMs, there is a disadvantage in that it is difficult to implement a CI module supporting each CAM to be driven normally, but the present invention is variously connected to the CI module 13. A list of the specific information of the CAM 14, that is, the CAM information table, is stored in the memory 18 in advance, and certain information is extracted from the predetermined CAM 14 inserted into the PCMCIA 13 of the CI module. By passing to the CI control unit 12, the normal operation of the inserted CAM 14 is supported to overcome the conventional problem.

Here, the common interface (CI) control unit decodes the digital broadcast signal by executing each program corresponding to the type of the CAM based on the information stored in the memory 18, and the CPU 17 stores the CAM stored in the memory. The information table identifies the type of the CAM and transmits it to the common interface (CI) control unit 12.

That is, the CI control unit 12 may know predetermined information about each of the plurality of CAMs through the memory 18 and the CPU 17, and the CI module 13 may be inserted into the PCMCIA. Specific information of the inserted CAM is extracted from the CAM 14 and transmitted to the CI control unit 12.

Accordingly, the CI control unit 12 receiving the specific information compares the specific information with information about each of the plurality of CAMs obtained through the memory 18 and the CPU 17, and compares the connected CAM 14 with each other. By judging the characteristics of), the connected CAM 14 can support the normal operation, that is, to decrypt the encrypted and received TS more accurately.

Therefore, according to the present invention, it is possible to implement a CI module supporting each CAM connected to the CI module 13 to be normally driven.

Here, as the specific information, information related to the manufacture of the predetermined CAM, such as an application_manufacturer and a manufacturer_code, for the predetermined CAM 14 may be used.

In other words, the CAM information table recognizes a type of a predetermined CAM connected to the PCMCIA through various CAM information tables stored in the memory in advance, wherein the CAM information table is based on application _ manufacturer and manufacturer _ code information. It is organized by classification.

Table 1 shows Application Info object coding in the case of the Common Interface Specification For Conditional Access and other Video Broadcasting Decoder Application standards. Referring to this, as an embodiment of the specific information, application_manufacturer, manufacturer_ code, etc.                     

2 is a method showing a conditional access method of a digital broadcast receiver according to the present invention.

This is due to the conditional access system of the present invention shown in FIG.

Referring to FIGS. 1 and 2, a method of conditional access of a digital broadcast signal for decrypting the digital broadcast signal TS of a predetermined channel, which is encrypted and transmitted, will be described below.

First, specific information is extracted from the CAM 14 connected to the common interface (CI) module 13. (ST 20)

Here, the CAM 14 can decrypt only an encrypted TS corresponding to a predetermined channel among TSs of various channels, and the predetermined CAM 14 is replaced with another CAM by accessing the CI module 13. It can be.

In addition, in the memory 18 of the conditional access system according to the present invention, a CAM information table for each of the various CAMs is stored in advance, and the specific information is referred to as an application_menupackage for each CAM. ) And information related to the manufacture of each of the CAMs, such as a manufacturer_code.

Next, the type of CAM corresponding to the specific information is identified by referring to the CAM information table previously stored in the memory. (ST 21)

This is done by the CPU 17, i.e., the CPU 17 grasps the type of the corresponding CAM by the CAM information table stored in the memory and delivers it to the common interface (CI) controller 12. will be.

Finally, one or more programs corresponding to the type of CAM are executed to decode the digital broadcast signal. (ST 22)

In this case, the execution of one or more programs corresponding to the type of the CAM is performed by reading a program list associated with the type of the CAM and executing the programs corresponding to the list of each step. It consists of individual programs.

That is, when the type of the CAM is determined by the memory 18 and the CPU 17, the program list related to the CAM is read, and the program corresponding to the read list of each step is executed to the CAM. Digital broadcast signal is decoded.

This is done by the common interface control unit 12, and will be described in detail with reference to Table 2. When the type of the CAM is recognized based on the specific information, the TS is decoded in the related SW by the information of the table shown in Table 2.

That is, when the predetermined CAM 14 connected to the PCMCIA 13 is identified as CAM_ # 3, SW2-1 in Stage 2 and SW4- in Stage 4, which are not in the order of SW1, SW2, SW3, and SW4 due to the characteristics of the CAM. Since 2 is executed, SW1, SW2-1, SW3, and SW4-2 are executed as a whole.

As a result, through the above steps, the connected CAM 14 supports normal operation, that is, decryption of the encrypted TS received more accurately.

According to the conditional access system and method of the digital broadcast signal according to the present invention as described above, the predetermined information is extracted from the predetermined CAM inserted into the PCMCIA of the CI module and delivered to the CI control unit, the CI control unit through this By supporting the inserted CAM to operate normally, there is an advantage that conditional access of a more efficient digital broadcast signal is possible.

In addition, instead of creating and executing all SWs according to each CAM separately, it separates each stage and executes a common SW and independent SWs corresponding to each CAM, minimizing waste of memory space and operating an efficient CAM. There is an advantage that it can.

Claims (6)

A conditional access system of a digital broadcast signal for decrypting a digital broadcast signal (TS) encrypted and transmitted, A predetermined conditional access module (CAM); A common interface (CI) module coupled to any conditional access module, for extracting and outputting specific information from the combined conditional access module; And The specific information is compared with the pre-stored CAM information table to recognize the type of the CAM coupled to the CI module, and sequentially execute one or more applications corresponding to the recognized type of CAM so that the combined CAM becomes the digital. A conditional access system for digital broadcast signals, comprising: a common interface control unit controlling to decode a broadcast signal. According to claim 1, And the specific information is an application_manufacturer or a manufacturer_code for the conditional access module. A conditional access method of a digital broadcast receiver for decrypting a digital broadcast signal (TS) encrypted and transmitted, Extracting specific information from a conditional access module (CAM) connected to a common interface module; Identifying a type of CAM corresponding to the specific information by referring to a CAM information table previously stored in a memory; And Executing one or more applications corresponding to the identified type of CAM to control a conditional access module connected to the common interface module to decode the digital broadcast signal. The method of claim 3, wherein Running at least one application corresponding to the type of CAM, And reading out an application list associated with the type of the CAM, and sequentially executing the applications corresponding to the application lists. delete The method of claim 3, wherein And the specific information is information including an application_manufacturer and a manufacturer_code for the CAM.

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