CN101584213B - Transmission and reception apparatus and method used in terrestrial digital multimedia broadcasting conditional access system - Google Patents

Abstract

Provided are transmission and reception apparatuses and methods for use in a conditional access system that limitedly allows access to a terrestrial digital multimedia broadcasting (T-DMB) service. The transmission apparatus selects a single service component from a transmission frame including a Main Service Channel (MSC) including a sub-channel including one or more service components and a Fast Information Channel (FIC) which transmits control information on the main service channel to insert an Entitlement Management Message (EMM) for authorizing or updating an entitlement on the DMB service to the selected single service component and provides location information on the selected single service component to the fast information channel.

Description

Transmission and reception apparatus and method used in terrestrial digital multimedia broadcasting conditional access system

technical field

The present invention relates to a transmission and reception device and method used in a conditional access system (conditional access system) that allows limited access to terrestrial digital multimedia broadcasting (T-DMB) services, and more particularly, to a device capable of A transmission and reception method and apparatus for reducing overhead of transmission bit rate by efficiently transmitting and receiving entitlement management messages (EMMs) of a T-DMB conditional access system.

Background technique

The conditional access system is a system that transforms an original broadcast signal such that the broadcast program can be provided only to receivers having rights with respect to the corresponding broadcast program. In this case, transforming the original broadcast signal so that the broadcast cannot be provided to unauthorized receivers is called scrambling, and the key used for the scrambling is called a control word.

Originally, the Terrestrial Digital Multimedia Broadcasting (T-DMB) conditional access standard was described in ETSI EN 300 401 Vl.3.3 Part 9, which is a T-DMB delivery standard. In this case, there are problems that the implementation according to ETSI EN 300 401 Vl.3.3 part 9 is complex and conditional access is not fully supported in the Multimedia Object Transfer (MOT) mode. Therefore, a new standard ETSI TS 102 367 Vl.2.1 has been introduced. However, this new conditional access standard is not compatible with the traditional conditional access standard and the ETSI EN 300 401 Vl.3.3 standard, but is compatible with the ETSI EN 300 401 Vl.4.1 standard revised in June 2006.

Contents of the invention

technical problem

According to the T-DMB conditional access standard (ETSI TS 102 367 Vl.2.1), in order to transmit a conditional access internal message, the conditional access internal message must be provided to each service component to be scrambled in a single ensemble. Each service component to be scrambled must be provided with an entitlement control message (ECM) including a control word corresponding to the scrambling key. However, when entitlement management messages (EMMs) are repeatedly provided to each service component, the overhead of transmitting the bit rate increases. In addition, when EMM is provided to a single service component and not to each service component, and the service component without EMM is to be delivered to the user, the user cannot receive the EMM, so that normal service cannot be provided.

As a method of delivering EMMs to a service component to be scrambled without repetition, a method for carrying EMMs to Fast Information Group (FIG) type 6 or subchannel number 63 (without payload transmission), or a method for carrying an EMM in an EMM-dedicated sub-channel and notifying the location of the EMM-dedicated sub-channel through a conditional access internal property field in FIG type 6. However, there is a problem that the two methods are not compatible with the ETSI TS 102 367 Vl.2.1 standard which is a new T-DMB conditional access standard.

Technical solutions

According to an aspect of the present invention, there is provided a transmitting device in a conditional access system allowing limited access to T-DMB services, the transmitting device comprising: an insertion position selector for selecting from channels including the main service channel and The transmission frame of the fast information channel selects a single service component, the main service channel includes sub-channels containing one or more service components, and the fast information channel transmits control information about the main service channel; the rights management message insertion unit uses inserting an entitlement management message for authorizing or renewing entitlement on T-DMB service to the selected single service component; and inserting a location provider for providing location information on the selected single service component to the fast information channel.

According to another aspect of the present invention, there is provided a delivery method for use in a conditional access system that allows limited access to T-DMB services, the delivery method comprising: (a) receiving a The transmission frame of the channel selects a single service component, the main service channel includes sub-channels containing one or more service components, and the fast information channel transmits control information about the main service channel; (b) to the selected single service The component inserts an entitlement management message for authorizing or renewing the entitlement on the T-DMB service; and (c) provides the fast information channel with location information on the selected single service component.

According to another aspect of the present invention, there is provided a receiving method used in a conditional access system that allows limited access to T-DMB (Terrestrial Digital Multimedia Broadcasting) services, the receiving method includes: (a) receiving receiving frames of a main service channel and a fast information channel, the main service channel comprising sub-channels containing one or more service components, and the fast information channel conveying control information about the main service channel; (b) from the fast information channel acquiring location information on a rights management message for authorizing or updating rights on the T-DMB service; and (c) extracting the rights management message from the main service channel by using the acquired location information.

Beneficial effect

Accordingly, instead of inserting the EMM of the T-DMB conditional access system to each service component to be scrambled, the EMM is inserted only to a single service component to be scrambled, so that it is possible to reduce the limitation of the transmission bit rate according to the conditional access service. overhead.

Description of drawings

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments of the present invention with reference to the accompanying drawings, in which:

1A and 1B are views illustrating structures of a transmission frame and a transmission protocol of Terrestrial Digital Multimedia Broadcasting (T-DMB) according to an embodiment of the present invention;

2 is a view illustrating the structure of a T-DMB conditional access system according to an embodiment of the present invention;

3 is a view illustrating the structure of a transmission device in a T-DMB conditional access system according to an embodiment of the present invention;

4A to 4C are views illustrating a data structure of a Fast Information Group (FIG) Type 6 that conveys Entitlement Management Message (EMM) location information according to an embodiment of the present invention;

Fig. 5 is the flowchart of the transmission method used in T-DMB conditional access system according to the embodiment of the present invention;

6 is a view illustrating the structure of a receiving device in a T-DMB conditional access system according to an embodiment of the present invention;

Fig. 7 is the flowchart of the receiving method used in T-DMB conditional access system according to the embodiment of the present invention; And

8 is a flowchart of a method for extracting and processing Entitlement Control Messages (ECMs) and EMMs by a receiving device in a T-DMB conditional access system according to an embodiment of the present invention.

Detailed ways

FIG. 3 is a view illustrating the structure of a transmission device in a T-DMB conditional access system according to an embodiment of the present invention.

Referring to FIG. 3 , the transmission device according to the current embodiment of the present invention includes: an insertion location selector 310 , a rights management message insertion unit 320 , and an insertion location provider 330 . With the aforementioned configuration, the transmitting device inserts the EMM and the EMM position information into the transmission frame to be transmitted.

The insertion position selector 310 selects a service component into which an EMM is to be inserted from among one or more service components included in the MSC 130 (see FIG. 1 ) transmitting the frame. Unlike the fact that ECM and CASyncParam are inserted into every service component included in MSC 130, EMM is inserted only in selected service components. Therefore, the overhead of the transmission bit rate according to the repeated transmission of EMM can be reduced.

A service component with a high frequency of use is selected as a single service component into which the EMM is inserted. This can increase the efficiency of the terminal. When the EMM is delivered to a service component with a low frequency of use, a situation in which the service component actually provided to the subscriber and the service component including the EMM (i.e., two service components) must be simultaneously processed in the terminal frequently occurs, and this It may lead to degradation of terminal efficiency, power consumption, etc.

As a method for measuring the frequency of use, for example, there is a method of measuring the frequency of use based on the number of charged subscribers when a service component is charged. In addition, there is a method for measuring frequency of use by using audience measurement research.

The rights management message inserting unit 320 inserts an EMM into a single service component selected by the inserting position selector 310 . The method for inserting the EMM into the selected service component is determined according to the scope in which the selected service component is scrambled (ie, according to the conditional access mode of the selected service component).

When the selected service component is scrambled in subchannel mode (CAMode 420 is "000"), i.e. when the conditional access mode of the selected service component is subchannel mode, an EMM is inserted into the selected service In the Subchannel Conditional Access Prefix (SUBCAPrefix) field of the subchannel to which the component belongs.

SUBCAPrefix is used to convey conditional access internal messages to the header field of the subchannel scheduled before scrambling the content.

When the selected service component is scrambled in data group mode (CAMode 420 is "001") or in MOT mode (CAMode 420 is "010") (that is, the conditional access mode of the selected service component is in the data group mode or MOT mode), insert EMM into the data field of the MSC data group.

When an EMM is not inserted into a designated position, an EMM is inserted into each service component included in the MSC 130.

The insertion location provider 330 carries information in the FIC 120 of the transport frame indicating the location of the service component into which the EMM is inserted.

The insertion location provider 330 uses the CAIntChar field in FIG type 6 in the FIC 120 as a location for delivering EMM location information. The CAIntChar field conveys conditional access internal characteristics, such as the version of the conditional access system used for the conditional access service, the applied algorithm, system specific parameters, channel ID, length information, and the like.

FIG. 5 is a flowchart of a transmission method used in a T-DMB conditional access system according to an embodiment of the present invention.

Referring to FIG. 5 , the transfer method according to the present embodiment includes operations performed by the transfer device illustrated in FIG. 3 in chronological order. Therefore, the foregoing description of the transfer device illustrated in FIG. 3 can be applied to the transfer method according to the present embodiment.

First, a single service component is selected from among one or more service components included in the MSC 130 (see FIGS. 1A and 1B ) transmitting the frame (operation S510). A service component with a high frequency of use is selected as a single service component into which the EMM is inserted.

Then, the EMM is inserted into the service component selected in operation S510 (operation S520). The method of inserting EMM into the SUBCAPrefix field of the subchannel to which the service component belongs or in the MSC packet data field is used as the range in which the selected service component is scrambled (i.e., the condition of the selected service component access mode) to insert the EMM into the selected service component. When the EMM is not inserted into the designated position, the EMM is inserted into each service component included in the MSC 130 .

Location information about the service component selected in operation S510 is carried in the FIC 120 (see FIGS. 1A and 1B ) transmitting the frame (operation S530). As a location for conveying EMM location information in FIC 120, the CAIntChar field in FIG type 6 is used. According to the conditional access mode of the service component, the EMM location information is a sub-channel identifier, or a sub-channel identifier and a service component identifier.

FIG. 6 is a view illustrating a structure of a receiving device in a T-DMB conditional access system according to an embodiment of the present invention.

Referring to FIG. 6 , the receiving device according to the current embodiment of the present invention includes: an EMM location acquisition unit 610 and an EMM extractor 620 . With this configuration, the receiving device extracts the EMM from the received frame, and takes the rights of the service component from the EMM, so that the scrambled service component can be provided to the receiving device.

The EMM position acquisition unit 610 acquires position information on the inserted EMM from the FIC 120 (see FIGS. 1A and 1B ) receiving the frame. The CAIntChar field of FIG type 6 is used as a location in the FIC 120 to include EMM location information. The receiving device receives conditional access internal characteristics through the CAIntChar field in FIG type 6, such as the version of the conditional access system used for the conditional access service, the applied algorithm, system specific parameters, channel ID, length information, etc.

If the conditional access mode (CAMode) 420 as a service component indicated by the EMM location information in the EMM location information acquired from the CAIntChar field of FIG type 6 is a subchannel mode ("000"), SubChId 410 is extracted. If the CAMode 420 of the service component indicated by the EMM location information is the packet mode ("001") or the MOT mode ("010"), the SubChId 410 and the SCId 430 are extracted.

The EMM extractor 620 extracts the EMM from the MSC 130 (see FIGS. 1A and 1B ) receiving the frame by using the location information acquired by the EMM location acquisition unit 610. If the CAMode 420 of the service component indicated by the EMM location information is in the subchannel mode (“000”), the EMM is extracted from the SUBCAPrefix field of the subchannel indicated by the SubChId 410. When the CAMode 420 of the service component indicated by the EMM location information is in the data group mode ("001") or MOT mode ("010"), it is extracted from the MSC data group data field of the service component indicated by the SubChId 410 and SCId 430 EMM.

When the position information acquired by the EMM position acquisition unit 610 has a predetermined value (for example, "11111111") representing a state in which an EMM is not inserted only into a single service component, the EMM extractor 620 extracts from each A service component extracts the EMM.

FIG. 7 is a flowchart of a receiving method used in a T-DMB conditional access system according to an embodiment of the present invention.

Referring to FIG. 7 , the receiving method according to the current embodiment includes operations performed by the receiving device illustrated in FIG. 6 in chronological order. Therefore, the foregoing description of the receiving device illustrated in FIG. 6 can be applied to the receiving method according to the present embodiment.

First, a reception frame including the MSC 130 and the FIC 120 is received (operation S700).

The location information on the service component into which the EMM is inserted is acquired from the FIC 120 (see FIGS. 1A and 1B ) of the reception frame received in operation S700 (operation S710). As a location in the FIC 120 into which EMM location information is inserted, a CAIntChar field of FIG type 6 is used. SubChId 410 is extracted, or SubChId 410 and SCId 430 are extracted according to CAMode 420 of the service component indicated by the EMM location information in the EMM location information acquired from the CAIntChar field of FIG type 6.

Then, the EMM is extracted from the MSC 130 (see FIG. 1 ) receiving the frame by using the location information on the service component acquired in operation S710. According to the CAMode 420 of the service component indicated by the EMM location information, the EMM is extracted from the SUBCAPrefix field of the subchannel indicated by the extracted SubChId 410, or from the MSC data set of the service component indicated by the extracted SubChId 410 and SCId 430 The data field extracts the EMM.

When the location information acquired in operation S710 has a value representing a state in which the EMM is not inserted into only a single service component, the EMM is extracted from each service component included in the MSC 130.

invention model

1A and 1B are views illustrating structures of a transmission frame and a transmission protocol of terrestrial digital multimedia broadcasting (T-DMB) according to an embodiment of the present invention.

Referring to FIG. 1A , a transmission frame (aggregate frame) of T-DMB includes: a synchronization channel 110 , a fast information channel (FIC) 120 , and a main service channel (MSC) 130 .

The synchronization channel 110 includes information used to synchronize each transmission frame.

The FIC 120 includes multiplex configuration information, service information, etc. for enabling receivers to quickly access information. In addition, the FIC 120 includes a plurality of Fast Information Blocks (FIBs), and each FIB includes a plurality of Fast Information Groups (FIGs). FIC 120 (rather than MSC 130) communicates parameters for the conditional access service (such as whether conditional access is applied, the conditional access mode applied, etc.), and signaling associated with the conditional access. Specifically, FIG type 6 in the FIC 120 is used to convey parameters associated with conditional access. For example, conditional access internal characteristics (CAIntChar), such as the version of the conditional access system for the conditional access service, applied algorithms, system specific parameters, channel identification (ID), length information, etc., are passed.

MSC 130 includes multiple sub-channels, and each sub-channel includes one or more service components. The MSC 130 delivers DMB content corresponding to payloads and conditional access internal messages such as Entitlement Management Messages (EMMs) and Entitlement Control Messages (ECMs).

The broadcast data of the T-DMB is multiplexed hierarchically according to the characteristics of the service components, and finally multiplexed to have a single aggregate frame type for transmission. In the conditional access standard, a mode is selected from three conditional access modes as a sub-channel mode, a packet mode, and a multimedia object transfer (MOT) mode according to the class and characteristics of a corresponding service component, so as to apply the mode to conditional access.

Referring to FIG. 1B , the subchannel mode indicates that all subchannels of the MSC 130 are scrambled. More specifically, audio subchannel 131 , packet mode subchannel 132 , and streaming mode subchannel 133 , including program associated data (PAD) 135 , are scrambled.

The packet mode indicates that MSC packets 140 transmitted over the packet mode sub-channel 132 or PAD 135 are scrambled. Data transmitted through MOT Directory Mode 141 , MOT Header Mode 142 , Internet Protocol (IP) Tunneling 143 , and Transparent Data Channel (TDC) 144 are to be scrambled.

The MOT mode indicates to scramble some or all objects in the structure of the MOT directory mode 141 .

FIG. 2 is a view illustrating the structure of a T-DMB conditional access system according to an embodiment of the present invention.

Referring to FIG. 2 , the transmitter of the T-DMB conditional access system includes: a conditional access message encoder 210 , a control word generator 220 , a synchronizer 230 , a scrambler 240 , and an aggregate multiplexer 250 . The receiver includes: a demultiplexer 260 , a conditional access message decoder 270 , a synchronizer 280 , and a descrambler 290 .

Conditional Access Message Encoder 210 generates ECMs and EMMs.

The ECM contains encrypted control words. The ECM is transmitted periodically for security and at each transmission a new control word is encrypted.

EMM is used to grant or update rights on T-DMB services.

As mentioned above, the messages generated by the conditional access message encoder 210 are called conditional access internal messages (CAIntMessage).

The control word generator 220 generates a control word as a key for scrambling content, and transmits the generated control word to the synchronizer 230 .

The synchronizer 230 synchronizes the scrambling operation and the control word transfer operation. The control word generated by the control word generator 220 is transmitted to the scrambler 240 and the conditional access message encoder 210 via the synchronizer 230 . In addition, a conditional access synchronization parameter (CASyncParam) is generated to allow the operations performed by the receiver to decode the message and descramble the content to be synchronized with each other. A toggle signal indicating that the control word has changed is a required parameter in CASyncParam.

The scrambler 240 mixes and transforms the content by using the control word generated by the control word generator 220 as a key so that receivers without rights cannot access the content.

Multiplexer 250 multiplexes content scrambled by scrambler 240, conditional access internal messages generated by conditional access message encoder 210, and synchronization parameters generated by synchronizer 230, thereby generating a single set frame.

Demultiplexer 260 demultiplexes the aggregate frame into scrambled content, conditional access internal messages, and synchronization parameters.

The conditional access message decoder 270 analyzes the conditional access system internal messages received from the demultiplexer 260, thereby performing entitlement management, entitlement check, and control word handling.

The synchronizer 280 analyzes the conditional access synchronization parameters received from the demultiplexer 260 to synchronize the control word, and transmits the control word to the descrambler 290 .

The descrambler 290 descrambles the scrambled content received from the demultiplexer 260 by using the control word received from the conditional access message decoder 270 .

FIG. 8 is a flowchart of a method for extracting and processing ECMs and EMMs used in a receiving device of a T-DMB conditional access system according to an embodiment of the present invention.

Referring to FIG. 8, a frame including the MSC 130 and the FIC 120 is received (operation S800).

It is determined whether EMM location information exists in the CAIntChar field of FIG type 6 of the received frame (operation S810).

If there is no CAIntChar field, or there is no information on a specified location into which the EMM is inserted, the ECM and EMM included in the service component desired to be received are extracted (operation S820).

If there is information on the specified position into which the EMM is inserted in the CAIntChar field, the information on the specified position into which the EMM is inserted is stored in the buffer (operation S830).

The EMM inserted into the designated location is extracted, and if the same EMM does not exist in the buffer, the EMM is stored in the buffer (operation S840).

The ECM is extracted from the service component desired to be received, and the EMM stored in the buffer is also extracted to be used with the ECM, so that the desired service component is descrambled and can be normally provided (operation S850).

Claims (19)

1. A delivery device in a conditional access system that allows limited access to T-DMB (Terrestrial Digital Multimedia Broadcasting) services, the delivery device comprising: Inserting a position selector for selecting a single service component from a transport frame comprising a main service channel comprising sub-channels containing one or more service components and a fast information channel transmitting information about Control information of the main service channel; a rights management message insertion unit for inserting a rights management message for authorizing or updating rights on the T-DMB service to the selected single service component; and inserting a location provider for providing location information about the selected single service component to the fast information channel, Wherein, the rights management message inserting unit inserts the rights management message according to the conditional access mode representing the scope of the rights of the selected single service component. 2. The apparatus of claim 1, wherein the insertion position selector selects a single service component based on a frequency of use of the service components included in the main service channel. 3. The apparatus of claim 2, wherein the usage frequency is measured based on one or more of a number of subscribers to the service component included in the main service channel and an audience measurement study. 4. The apparatus according to claim 1 , wherein if the conditional access mode is in a subchannel mode, the entitlement management message inserting unit inserts the entitlement management message into the subchannel on which the selected single service component is arranged. conditional access prefix, and the insertion location provider provides the fast information channel with an identifier for the subchannel and a conditional access mode. 5. The apparatus according to claim 1, wherein, if the conditional access mode is in the data group mode, the rights management message inserting unit inserts the rights management message into the main service channel data group data field of the selected single service component , and the insertion location provider provides the fast information channel with an identifier of a subchannel on which the selected single service component is arranged, a conditional access mode, and an identifier for the selected single service component. 6. The apparatus according to claim 1, wherein, if the conditional access mode is in the multimedia object transfer mode, the entitlement management message inserting unit inserts the entitlement management message into the main service channel data set data of the selected single service component field, and the insertion location provider provides the fast information channel with an identifier for the subchannel on which the selected single service component is arranged, a conditional access mode, and an identifier for the selected single service component . the 7. The apparatus according to claim 1, wherein, if no single service component is selected, the entitlement management insertion unit inserts a entitlement management message into each service component included in the main service channel, and the insertion location provides The implementer provides the fast message channel with a value representing the state in which no single service component is selected. 8. A delivery method used in a conditional access system that allows limited access to T-DMB services, the delivery method comprising: (a) selecting a single service component from a transport frame comprising a main service channel comprising sub-channels containing one or more service components and a fast information channel conveying information about the main service channel control information; (b) inserting a rights management message for authorizing or updating rights on the T-DMB service to the selected single service component; and (c) provide fast information channels with location information about selected single service components, Wherein, in step (b), the rights management message is inserted according to the conditional access mode representing the scope of the rights of the selected single service component. 9. The method of claim 8, wherein in the step (a), a single service component is selected based on a frequency of use of the service components included in the main service channel. 10. The method of claim 9, wherein the frequency of usage is measured based on one or more of a number of subscribers to a service component and an audience measurement study. 11. The method according to claim 8, wherein, if said conditional access mode is in subchannel mode, then in step (b), an entitlement management message is inserted into the subchannel on which the selected single service component is arranged. In the conditional access prefix, and in step (c), the fast information channel is provided with an identifier for the subchannel and a conditional access mode. 12. The method according to claim 8, wherein, if the conditional access mode is in the data group mode, then in step (b), the entitlement management message is inserted into the main service channel data group data field of the selected single service component , and in step (c), the fast information channel is provided with the identifier of the subchannel on which the selected single service component is arranged, the conditional access mode, and the identifier for the selected single service component . 13. The method according to claim 8, wherein, if the conditional access mode is in the multimedia object transfer mode, then in step (b), the entitlement management message is inserted into the main service channel data group data of the selected single service component field, and in step (c), the fast information channel is provided with the identifier of the subchannel on which the selected single service component is scheduled, the conditional access mode, and the identifier. 14. The method according to claim 8, wherein, if no single service component is selected, in step (b), entitlement management messages are inserted into each service component included in the main service channel, and in step (c ), a value representing the state in which no single service component is selected is provided to the fast message channel. 15. A reception method used in a conditional access system that allows limited access to T-DMB (Terrestrial Digital Multimedia Broadcasting) service, the reception method comprising: (a) receiving a receive frame comprising a main service channel and a fast information channel, the main service channel comprising sub-channels comprising one or more service components, and the fast information channel conveying control information about the main service channel; (b) Obtain location information from the fast information channel on rights management messages used to authorize or update rights on T-DMB services; and (c) extracting entitlement management messages from the main service channel by using the acquired location information, Wherein, in step (a), the location of the service component is extracted from the acquired location information according to a conditional access pattern representing a range of rights for limiting the service component into which the rights management message is inserted. 16. The method of claim 15, wherein, if the conditional access mode is in a sub-channel mode, in step (b), a sub-channel identifier is extracted from the acquired location information, and in step (c), The rights management message is extracted from the conditional access prefix of the subchannel indicated by the extracted subchannel identifier. 17. The method according to claim 15, wherein, if the conditional access mode is in the data group mode, in step (b), the identifier for the subchannel and the identifier for the service component are extracted from the acquired location information. identifier, and in step (c), the entitlement management message is extracted from the main service channel data group data field of the service component indicated by the extracted subchannel identifier and the extracted service component identifier. 18. The method according to claim 15, wherein, if the conditional access mode is in the multimedia object transfer mode, then in step (b), the subchannel identifier and the service component identifier are extracted from the acquired location information, and in In step (c), the rights management message is extracted from the data field of the main service channel data group of the service component indicated by the extracted sub-channel identifier and service component identifier. 19. The method according to claim 15, wherein in step (c), if in step (b) a value representing a state of not inserting a rights management message to a single service component is extracted, then from the included in the main service channel Each service component extracts entitlement management messages. the

Images