KR20070100073A - A receiving apparatus and a receiving method for broadcasting - Google Patents

Abstract

A method and an apparatus for receiving broadcast are provided to compare an address mapped to a received IP(Internet Protocol) address with an address of a host, thereby performing a limitation access function by simply performing inter-certification without additional devices such as a smart card. An apparatus for receiving broadcast comprises the followings: an inter-certification unit for performing inter certification and an address of a host by outputting IP(Internet Protocol) address from a received IP data grab by encapsulation of a predetermined format; and a descrambler(432) for performing descramble when inter-certification is realized in the inter-certification unit. The inter-certification unit has a host address outputting unit(413) for outputting an address of a host, a comparing unit(411) for comparing an encapsulated IP address with the outputted host address, and a certification unit(412).

Description

A receiving apparatus and a receiving method for broadcasting

1 is a diagram showing an embodiment of a general digital multimedia broadcasting service structure

2 is a schematic diagram of a broadcast transmitter capable of transmitting broadcasts according to an embodiment of the present invention;

3 is a signal flow diagram of a broadcast transmitter according to an embodiment of the present invention;

4 is a schematic diagram of a broadcast receiver capable of receiving a broadcast according to an embodiment of the present invention;

5 and 6 are signal flow diagrams of a broadcast receiver according to an embodiment of the present invention.

7 is a schematic flowchart of a broadcast receiving method according to the present invention;

8A and 8B are detailed flowcharts of a broadcast receiving method according to an embodiment of the present invention.

9 is a tunneling process diagram of an IP datagram

10 is a protocol stack characteristic diagram for IP tunneling

* Description of the symbols for the main parts of the drawings *

210: scrambler 211: first scrambler

212: second scrambler 213: third scrambler

410: mutual authentication module 411: comparison unit

412: authentication unit 413: host address extraction unit

420: descrambler 421: first descrambler

422: second descrambler 423: third descrambler

The present invention relates to a broadcast receiver and a broadcast receiving method, and more particularly, to a broadcast receiver and a broadcast receiving method for enabling limited reception.

Digitalization of broadcasting is progressing rapidly through existing media such as terrestrial, satellite, and cable broadcasting, and is revolutionizing the environment of the broadcasting industry. Due to such environmental changes, a newly emerged medium is a broadcast receiver capable of receiving mobile broadcast.

There may be various broadcast receivers capable of receiving the mobile broadcast. For example, there are terminals such as digital multimedia broadcasting (DMB), digital video broadcasting-handheld (DVB-H), and media flow. The broadcast receiver applies a broadcast reception function to a personal portable terminal such as a mobile phone, a PDA, a notebook computer, a vehicle terminal, and provides various multimedia broadcasts to a user while moving or in a fixed place.

In particular, terrestrial digital multimedia broadcasting (DMB) has evolved from listening to watching and listening to broadcasting. The terrestrial DMB is based on Eureka-147 Digital Audio Broadcasting (DAB), which has been adopted as the European terrestrial radio standard. Added to improve multimedia broadcasting performance, RS codes (Reed-Solomon Code) and convolutional interleaver that are robust against burst errors that may occur on a transmission channel are added. The two additional blocks are applied to the DAB Ensemble input signal at the transmitter and provide an error rate low enough for video service even in a mobile receiving environment.

In addition, the transmission channel of the DMB broadcast is a wireless mobile reception channel, and the amplitude of the received signal is not only time-varying, but also the Doppler Spreading of the spectrum of the received signal due to the influence of the mobile receiver. Occurs.

In consideration of the transmission and reception in such a channel environment, the DMB transmission method uses differential coding based on Orthogonal Frequency Division Multiplexing (OFDM).

At this time, the DMB transmission signal is transmitted with a very small signal strength compared to the existing analog radio broadcasting signal, and considering the mobile reception as in a car in a severe fading channel environment such as downtown, the signal strength of the actual received signal is Very small Therefore, a broadcast receiver capable of receiving DMB should be able to receive a received signal as much as possible in such a poor reception environment and correct a transmission error. In addition, considering the fact that it is a mobile terminal, providing the maximum reception performance at a limited cost is a key requirement of a broadcast receiver configuration.

In such a DMB, at least one ensemble corresponding to one physical channel frequency range may be serviced.

1 illustrates an example of one ensemble structure, in which one ensemble is composed of at least one service, and each service is composed of at least one service component.

The service corresponds to one channel of TV or radio. The service component means video, audio, traffic information, or broadcast service information constituting a broadcast. The service component may come from each sub-channel of the main service channel (MSC) and the fast information data channel (FIDC).

The multiplexing configuration information (MCI) is used to indicate what services are multiplexed in the ensemble, what service components constitute each service, and where the service components are located. That is, the MCI includes information on how the MSC is configured in the same frame, and the SI includes information on what services are provided through the MSC.

The MCI is transmitted through a fast information channel (FIC) in a DMB transport frame.

That is, the DMB transmission frame is composed of a synchronization channel (Fynchronization Channel), a fast information channel (FIC), and a main service channel (MSC).

The synchronization channel has a predetermined form so that the DMB receiver recognizes the beginning of the frame, and a null symbol and a phase reference symbol (PRS) are allocated.

The FIC is used to transmit various types of information for receiving a broadcast service, and is composed of an MCI, a service information (SI), and a fast information data channel (FIDC).

The MSC is composed of one or more Common Interleaved Frames (CIFs), and is used for transmitting broadcast services such as video, audio, and data. The smallest unit that can allocate an address in one CIF is a capacity unit (CU), and a plurality of CUs are connected to form one subchannel. In order to transmit the service component of the MSC, two data transmission modes, a stream mode and a packet mode, are supported.

In other words, the control information FIC contains information indicating the structure of data carried in the CIF in the MSC, which is data information, and each CIF contains actual data such as video data and audio data. The biggest difference between the FIC and the MSC depends on whether it is time de-interleaving and transmitted. The FIC is not time interleaved, the MSC is time interleaved, and most of the data is transmitted through the MSC.

And the data service that can be provided by DMB is various. For example, Program Associated Data (PAD) and Independent Data (N-PAD; Non Program Associated Data), Service Information (SI), Multimedia Object Transfer (MOT) slideshow, Broadcast Web Site BWS), Interactive Services, and Live Video Services.

The transmission mode most commonly used in the data transmission is a packet mode, in which data is divided into data groups. In addition, the MOT protocol is a transmission protocol for delivering a multimedia object (ie, content) using a data channel to various types of receivers capable of receiving multimedia decode. The targets of the MOT protocol are text, images, video, and audio. At this time, in the terrestrial DMB, the MOT transmission makes the multimedia object into the MOT standard and then transmits it in packet mode or PAD.

In such DMB, there is also a need for restrictive access (CA) for the purpose of charging for paid services or viewing age-restricted services. Herein, various terms such as scramble and encryption are used as the CA method, and the scramble includes encryption and descramble includes decryption. Currently, there is no limited reception function in an audio / video / data receiver such as DMB, and thus there is no way to provide a paid service. In addition, in order to provide a paid service, inconvenience may occur when using an external smart card.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a broadcast receiver and a broadcast receiving method for enabling limited access.

Another object of the present invention is to provide a broadcast receiver and a broadcast receiving method for enabling direct mutual authentication between a broadcast transmitter and a broadcast receiver through IP tunneling.

It is still another object of the present invention to provide a broadcast receiver and a broadcast reception method that can be adapted to a limited reception system for each broadcaster by providing a limited reception algorithm by a plurality of bidirectional communication providers.

In order to achieve the above object, the present invention extracts an IP address from a received IP datagram encapsulated in a predetermined format, and performs mutual authentication with the host's address and mutual authentication is established in the mutual authentication means. The present invention provides a broadcast receiver comprising a descrambler for performing descramble.

According to another embodiment of the present invention, mutual authentication means for extracting an IP address from the received IP datagram encapsulated in a predetermined format and performing mutual authentication with an address of a host, and feeding back an authentication result of the bidirectional communication means to a broadcaster. The present invention provides a broadcast receiver comprising a descrambler configured to perform descramble when mutual authentication is established in the mutual authentication means.

According to another embodiment of the present invention, receiving an IP datagram encapsulated in a predetermined format, extracting an IP address, mutually comparing the IP address with an address of the host, and verifying the qualification by mutual authentication. It provides a broadcast receiving method comprising the step of performing a scramble.

According to another embodiment of the present invention, the method comprises: extracting an IP address by receiving an IP datagram;

Comparing the IP address and the address of the host, the mutual authentication, transmitting the result of the mutual authentication to the broadcaster in two-way communication, and if the qualification is confirmed by mutual authentication, performing a descramble It provides a broadcast receiving method.

Therefore, according to the present invention, a limited access function can be performed by simply performing mutual authentication by comparing an address mapped to a received IP address with an address of a host.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described. At this time, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, by which the technical spirit of the present invention and its core configuration and operation is not limited.

In addition, the terminology used in the present invention is a general term that is currently widely used as much as possible, but in certain cases, the term is arbitrarily selected by the applicant. In this case, since the meaning is described in detail in the description of the present invention, The present invention should be grasped by the meaning of the term and not the name.

2 shows a schematic structure of one embodiment of a broadcast transmitter, and FIG. 3 shows a signal flow of an embodiment of a broadcast transmitter.

2 and 3, a scrambler 210 capable of performing conditional access (CA, hereinafter referred to as CA) in a conventional DMB system may have various paths. In the present invention, three paths are used as examples for convenience of description, and each of the first scrambler (sub channel CA mode, 211), the second scrambler (data group CA mode, 212), and the third scrambler (MOT CA mode, 213).

The first scrambler 211 is a mode for performing scramble at a sub channel stage, and all data included in the sub channel is scrambled. That is, it is possible to scramble all of a specific subchannel such as the audio stream 201, the packet mode channel 203, and the stream mode channel 204 including the PAD.

The second scrambler 212 is a mode for performing scramble at the data group end, and encrypts all DMB data transmission protocols 202 such as IP tunneling, MOT, TDC, etc. using the MSC data group. That is, data not included in the data group is not scrambled. In this case, scrambled data and scrambled data may exist in one subchannel. For example, the audio program may not be scrambled in one sub-channel, but only data scrambled in the data group stage may be scrambled.

The third scrambler 213 is a mode for performing scramble at the MOT stage, and is applied to files 205 transmitted using the MOT directory mode.

In the present invention, since the IP address included in the header of the IP datagram is used for mutual authentication in the scramble and descramble processes, the IP datagram is encapsulated and transmitted. At this time, IP datagrams are scrambled together at the scrambled stage.

Encapsulation refers to a technique for embedding and transmitting communication protocol information of a higher layer in a lower communication protocol frame user information area when a specific format is required to use a path between data transmission and reception modules. In other words, it is a process that aggregates information in a plurality of protocol layers into a communication network. Examples of encapsulation include tunneling, datacasting, multiprotocol encapsulation, and the like. In the present invention, the tunneling as a representative embodiment of the encapsulation, for convenience of description, it will be described using tunneling. The present invention is not limited by the above embodiments.

IP tunneling is a technology for encapsulating the network communication protocol used in each network environment into IP communication protocol and enhancing safety when IP packetizing data in a virtual private communication network (VPN) on the Internet. For example, if the headquarters network and the branch office network each use a network communication protocol called IPX, then the IP communication protocol at each Internet outlet to use the Internet connecting the main office and the branch office. Encapsulate with. That is, a technique for encapsulating data.

4 shows a schematic configuration of a broadcast receiver according to the present invention, and FIG. 5 shows a signal flow of an embodiment of the broadcast receiver according to the present invention.

4 and 5, the broadcast receiver according to the present invention includes a mutual authentication means 410 and a descrambler 420.

The mutual authentication means 410 includes a comparator 411, an authenticator 412, and a host address extractor 413.

The mutual authentication means 410 is a means for confirming whether the host receiving the broadcast signal is a legitimate host before decrypting the encrypted broadcast signal. The present invention proposes to use a method of comparing an IP address of an IP (Internet Protocol) datagram with a unique address of the host in order to confirm whether it is such a legitimate host.

If the broadcast signal received through the tuner 401 and the receiver 402 is encrypted, the mutual authentication means 410 operates before decrypting the encryption.

The host address extractor 413 extracts a host address that is information unique to each host. In the present invention, a MAC address (media access control address) is used as an embodiment.

The comparison unit 411 and the authentication unit 412 extracts an IP address from the decapsulated IP datagram and finds host information mapped to the IP address. The mapping table of the IP address and the host information exists in the broadcast receiver. The identity is determined by comparing the mapped host information with the host address extracted by the host address extractor. If the host information and the host address are the same, the descrambler operates by being authenticated as a valid host. On the other hand, if it is determined that the host information and the host address are not the same, the descrambler does not work because the host is not valid. In this case, the subchannel is selected again. The roles of the comparison unit and the authentication unit are not strictly distinguished, and perform the above roles.

The broadcast receiver according to the present invention may include a bidirectional communication means. When the broadcast receiver includes a bidirectional communication means such as a mobile mobile terminal or a PDA, the entitlement management message may be received through the bidirectional communication means. Therefore, when there are a plurality of broadcast providers and a plurality of limited reception system providers, the number of algorithms of the limited reception system is plural, so that a problem can be solved by one communication service provider managing the problem at the time of manufacture of the broadcast receiver.

The authentication unit is formed of an externally open module, and may receive a control signal such as a qualification management message on an external communication line. According to an embodiment, an entitlement management message (EMM) may be received from a communication service provider, the encryption of an entitlement control message (ECM), which is an encrypted descramble key, may be decrypted, and the descramble key may be handed over to the descramble key. At this time, the EMM may be performed to perform only a role of handing over the descramble. In this case, decryption of the ECM with the EMM is performed in the descrambling step. In addition, the result of the authentication can be fed back to the broadcaster via the communication line, thereby enabling more accurate restriction reception by double mutual authentication.

The two-way communication means may be made by a communication service provider separate from the broadcast service provider. Therefore, billing systems such as prepaid, flat and postpaid are possible.

The descrambler 420 may exist as one using one algorithm, or may exist one per descrambler even if the same algorithm is used. The present invention provides an embodiment in which descrambling is performed in three stages.

Therefore, a first descrambler 421 for decrypting the encryption of the sub-channel stage, a second descrambler 422 for decrypting the encryption of the data group stage, and a third descrambler 423 for decrypting the encryption of the data stage. . At this time, the step of decrypting by the third descrambler may be a single MOT.

FIG. 7 illustrates data required for descrambled in accordance with the limited reception standard of the broadcast receiver according to the present invention and flow thereof, and FIGS. 8A and 8B illustrate the flow of such data in more detail.

Referring to FIG. 7, a general descrambling process is performed. After receiving a broadcast, a subchannel is selected, and it is determined whether the subchannel is scrambled. If the subchannel is not scrambled, the first descrambling step is not performed, and if the subchannel is scrambled, the first descrambling step is received by receiving a descramble key. ECM is presented as a descramble key in the figure. This is only an embodiment, and the ECM is an encrypted descramble key. However, in the authentication step, the ECM may be decrypted and only the descramble key may be delivered. Only the mutual authentication result is transmitted to the descramble step. May be decrypted and the descramble step may proceed. The above description is equally applicable to the following second and third descramble processes, and the descramble key will be described with an embodiment ECM. However, the present invention is not limited by this embodiment. When the user selects one subchannel, available channels are a stream channel and a packet channel. If the subchannel is scrambled, it is descrambled using the information provided by the ECM and the mutual authentication module. This is divided into a stream and a packet and proceeds to the next step. If it is a stream, it is output (output 1), and if it is a packet, data demultiplexing is used to create a data group.

If not scrambled in the sub-channel but scrambled in the data group, the second descrambling step is performed. If the data group is not scrambled, the data group is bypassed. If scrambled, the data group is descrambled using information provided by the ECM and the mutual authentication module, and the ECM may be used in the third descrambling process. This is because the second descrambling process and the third descrambling process may be performed in parallel. The second descrambled data group is disassembled, and is output as an IP datagram transmitted by MOT or IP tunneling. In case of IP datagram, output 3 is used in the next step. In the case of the MOT, since only the MOT may be scrambled, the ECM extracted through the MOT parsing and the ECM delivered in the second descrambling process may be used.

Referring to FIG. 8A, referring to a detailed signal flow of the first descrambling step, when a user selects a subchannel, the user receives data through one subchannel. If there is a SUBCAPrefix of the corresponding subchannel data, the SUBCAPrefix may be parsed to obtain a subchannel ID different from that of the ECM. At this time, if there is no SUBCAPrefix, the sub-channel is not encrypted, and the step of determining whether encryption of the data group stage is performed.

ECM is used to descramble scrambled data along with the information that passes the authentication process. Since an IP datagram cannot be extracted from an encrypted subchannel, another subchannel ID selects a subchannel to obtain an IP datagram, and passes the IP address in the header to the authentication process. Packet multiplexed streams and packets are passed to output 1 and data group processing, respectively.

Referring to FIG. 8B, referring to the detailed signal flows of the second descrambling step and the third descrambling step, the headers are classified into types obtained by parsing their headers starting from the data group. It demonstrates with an Example below. If the type is 0001 and 0005, it has ECM information, which is used to descramble the data group and the MOT. The IP address input for the authentication process is extracted by using the IP datagram obtained by analyzing data of another subchannel and the IP datagram obtained through the data group of this subchannel. The data group passes through the disassembly process (output 3) and, if the MOT itself is scrambled, goes to MOT parsing. The scrambled MOT is descrambled, and if not, the MOT is immediately output (output 2).

9 specifies a tunneling process and a scramble location of an IP datagram. IP datagrams go one-to-one into the data group data field of the MSC data group, which is sent in packets. To scramble an IP datagram, there are a method of scrambling the entire subchannel packet and a method of scrambling only data fields of the MSC data group.

10 shows each level in IP tunneling. The data obtained using the MSC data group is an IP datagram, which is used in the application desired by the user by moving up the Internet network layer.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

The effects of the broadcast receiver and the broadcast reception method according to the present invention described above are as follows.

First, by comparing the received IP address with the address of the host address, it is possible to perform a limited access function by simply performing mutual authentication without a separate device such as a smart card.

Second, by performing a restricted reception function through a two-way communication provider, it is possible to perform a more secure mutual authentication, it can be applied to a different reception system for each broadcaster with one descramble algorithm.

Claims (18)

Mutual authentication means for extracting an IP address from the received IP datagram encapsulated in a predetermined format and performing mutual authentication with an address of a host; And And a descrambler for descrambling when mutual authentication is established in the mutual authentication means. The method of claim 1, wherein the mutual authentication means A host address extracting unit extracting an address of the host; A comparing unit comparing the host address extracted by the host address extracting unit with the decapsulated IP address in the IP datagram; And And an authenticator configured to perform mutual authentication as a result of comparing the comparator. The method of claim 2, wherein the host address extraction unit And extracting a unique MAC address of the host and transferring the extracted unique MAC address to at least one of the comparator, the authenticator, and the descrambler. The method of claim 2, wherein the comparison unit, And obtaining host information mapped to the IP address, and determining the identity with the host address extracted by the host address extracting unit. The method of claim 2, wherein the authentication unit It is characterized in that open to receive external data, And decrypting the control key encrypted with the received entitlement management message to entitle the broadcast reception. The method of claim 1, wherein the descrambler A first descrambler for decrypting the subchannel stage; Second descrambler to decrypt data group end: And a third descrambler for decrypting the data stage. The method of claim 6, wherein the first descrambler, And outputting the non-scrambled subchannels by bypass, and descrambled the scrambled subchannels with a control key. The method of claim 6, wherein the second descrambler, The non-scrambled data group is bypassed and output, and the scrambled data group is descrambled with a control key. The method of claim 6, wherein the third descrambler, The unscrambled data is bypassed and output, and the scrambled data is descrambled with a control key. Mutual authentication means for extracting an IP address from the received IP datagram encapsulated in a predetermined format and performing mutual authentication with an address of a host; Bidirectional communication means for feeding back an authentication result of the bidirectional communication means to a broadcaster; And a descrambler for descrambling when mutual authentication is established in the mutual authentication means. Extracting an IP address by receiving an IP datagram encapsulated in a predetermined format; Mutually authenticating the IP address with a host address; And if the qualification is confirmed by mutual authentication, performing descramble. The method of claim 11, And receiving the IP datagram through IP tunneling. The method of claim 11, wherein the mutual authentication is performed. Mapping the IP address and host information; Extracting a host address from the host; And determining the identity of the mapped host information and the extracted host address. The method of claim 13, And determining the identity of the host information and the host address, and authenticating as a valid host if the identity is recognized. The method of claim 11, And the host address is a unique MAC address for each host. Receiving an IP datagram and extracting an IP address; Mutually authenticating the IP address with a host address; Transmitting a result of the mutual authentication to a broadcaster in two-way communication; And if the qualification is confirmed by mutual authentication, performing descramble. The method of claim 16, The two-way communication is broadcast receiving method characterized in that the communication is made by a separate entity. 17. The method of claim 16, wherein if a valid qualification is confirmed by mutual authentication, Receiving a credential management message; And decrypting the entitlement control key encrypted with the received entitlement management message.

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