Receiving device, broadcasting system, and receiving method

Abstract

Enhance the protection of broadcast content without requiring hardware changes. [Solution] The receiving processing unit detects notification information regarding the transmission of download data from the received signal. When the notification information contains limited reception processing program information indicating a limited reception processing program, the software update unit acquires download instruction information and download data blocks during the transmission period notified by the notification information. The software update unit extracts the limited reception processing program from the download data block containing download identification information common to the download identification information described in the download instruction information indicating the limited reception processing program information, and sets the extracted limited reception processing program in the limited reception processing unit.

Description

Technical Field

[0001] The present application relates to a receiving apparatus, a broadcasting system, and a receiving method.

Background Art

[0002] In digital television broadcasting, a conditional access system (CAS) may be adopted to protect the copyright of distributed content (for example, Patent Document 1). In advanced BS (Broadcasting Satellite) digital broadcasting and advanced broadband CS (Communication Satellite) digital broadcasting (4K / 8K broadcasting), A-CAS (Advanced CAS) is adopted. A-CAS enhances protection by adding a download function to the conventional B-CAS (BS CAS) system. The download function updates (updates) a program (which may be referred to as a "CAS program" in the present application) used for decrypting encrypted content. In advanced BS digital broadcasting and advanced broadband CS digital broadcasting, DCM (Download Control Message) and DMM (Download Management Message) are used in the transmission of the CAS program.

[0003] In addition, in a common receiving apparatus compatible with any of terrestrial digital broadcasting (2K broadcasting), conventional BS digital broadcasting (2K broadcasting), advanced BS digital broadcasting, and advanced broadband CS broadcasting, encrypted content distributed by any of these broadcasts can be received by A-CAS.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, in terrestrial digital broadcasting and BS digital broadcasting, content such as video and audio is transmitted using the TS (Transport Streaming) method. However, the TS method does not specify how the CAS program should be transmitted. Dedicated receiving equipment for either terrestrial digital broadcasting or BS digital broadcasting, or both, is expected to enhance content protection in response to CAS program updates. [Means for solving the problem]

[0006] This invention was made to solve the above problems, and one aspect of this invention is a receiving device comprising: a receiving processing unit that decrypts encrypted content from a received signal obtained by receiving a broadcast wave; a limited receiving processing unit that obtains a decryption key for decrypting the content according to a limited receiving processing program; an output processing unit that outputs the decrypted content; and a software update unit, wherein the receiving processing unit detects notification information regarding the transmission of download data from the received signal, and the software update unit, when the notification information contains limited receiving processing program information indicating a limited receiving processing program, obtains download instruction information and a download data block during the transmission period notified by the notification information, extracts a limited receiving processing program from a download data block containing download identification information common to the download identification information described in the download instruction information indicating the limited receiving processing program information, and sets the extracted limited receiving processing program in the limited receiving processing unit.

[0007] Another aspect of the present invention is a receiving method in a receiving device, which decrypts encrypted content from a received signal obtained by receiving a broadcast wave, obtains a decryption key for decrypting the content according to a restricted reception processing program, and outputs the decrypted content, wherein the receiving device detects notification information regarding the transmission of download data from the received signal, and when the notification information contains restricted reception processing program information indicating a restricted reception processing program, it obtains download instruction information and a download data block during the transmission period notified by the notification information, extracts a restricted reception processing program from a download data block containing download identification information common to the download identification information described in the download instruction information indicating the restricted reception processing program, and sets the extracted restricted reception processing program. [Effects of the Invention]

[0008] According to one embodiment of the present invention, the protection of broadcast content can be enhanced without requiring any hardware modifications. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic block diagram showing an example of the functional configuration of the broadcasting system according to this embodiment. [Figure 2] This is a schematic block diagram showing an example configuration of the software update unit according to this embodiment. [Figure 3] This flowchart shows the CAS program update process according to this embodiment. [Figure 4] This figure shows an example of the data structure for SDTT. [Figure 5] This is a list showing examples of values ​​assigned to table identification extensions. [Figure 6] This is an explanatory diagram illustrating an example of a CAS program identifier according to this embodiment. [Figure 7] This figure shows an example of the data structure of DII. [Figure 8] This figure shows an example of a compatibility descriptor configuration. [Figure 9] This is a diagram showing a configuration example of a CAS program descriptor according to this embodiment. [Figure 10] This is a flowchart exemplifying the download reservation process according to this embodiment. [Figure 11] This is a flowchart exemplifying the download start process of a CAS program according to this embodiment. [Figure 12] This is a schematic block diagram showing a functional configuration example of a broadcast system according to the second embodiment. [Figure 13] This is a diagram showing a setting example of a table identification extension according to the second embodiment. [Figure 14] This is a diagram showing the relationship between DDI messages and DDB messages according to the second embodiment. [Figure 15] This is a diagram showing a setting example of SDTT according to the second embodiment. [Figure 16] This is a diagram showing a setting example of DII according to the second embodiment. [Figure 17] This is a diagram showing a setting example of DDB according to the second embodiment. [Figure 18] This is a diagram showing a data configuration example of SDTT according to the second embodiment. [Figure 19] This is a diagram showing a data configuration example of a download content descriptor. [Figure 20] This is a diagram showing a data configuration example of DII according to the second embodiment. [Figure 21] This is a diagram showing a data configuration example of a compatibility descriptor. [Figure 22] This is a diagram showing a data configuration example of DDB according to the second embodiment. [Figure 23] This is a diagram showing a data configuration example of a dsmcc download data header descriptor. [Figure 24] This is a flowchart exemplifying the download reservation process in SDTT according to the second embodiment. [Figure 25] This is a flowchart exemplifying the download start process of a CAS program according to the second embodiment. [Figure 26]This figure shows an example of SDTT settings related to the notification of data common to all receivers. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, an overview of the broadcasting system S1 according to the embodiment of this application will be described. Figure 1 is a schematic block diagram showing an example of the functional configuration of the broadcasting system S1 according to this embodiment. The broadcasting system S1 comprises a receiving device 10 and a broadcasting device 20.

[0011] The receiving device 10 receives the content of broadcast programs (sometimes referred to as "broadcast content" in this application) transmitted via a broadcast network. The receiving device 10 is mainly installed in the homes, offices, or other facilities of the users, which are viewers. The receiving device 10 may be a dedicated television receiving device, or it may be implemented as another form of electronic device, such as a general-purpose information processing device like a personal computer.

[0012] The receiving device 10 acquires a data stream containing encrypted content from a received signal received using the broadcast network. The receiving device 10 extracts the encrypted content from the acquired data stream and decrypts the extracted encrypted content according to the CAS program. The receiving device 10 presents the decrypted plaintext broadcast content.

[0013] A broadcasting network is a transmission path that enables the simultaneous, one-way transmission of broadcast signals to unspecified destinations. A broadcasting network is also called a broadcasting transmission path. In terrestrial digital broadcasting, terrestrial waves are mainly used as the broadcasting network. Terrestrial waves are broadcast waves transmitted from ground stations. Broadcasting networks related to BS digital broadcasting include artificial satellites in addition to ground stations. Artificial satellites relay broadcast waves transmitted from ground stations. However, a part of the broadcasting network may be physically composed of wireless or wired communication networks, which may be used for transmitting content from broadcasting stations to ground stations. In this application, a broadcasting network may be simply referred to as a "network."

[0014] The receiving device 10 extracts notification information regarding the transmission of downloaded data from the acquired data stream and detects an identifier related to the CAS program from the extracted notification information. The receiving device 10 receives the CAS program notified in the notification information and updates the existing CAS program with the newly received CAS program. Thereafter, the updated CAS program is used to decrypt the encrypted content.

[0015] The broadcasting equipment 20 is primarily managed by the broadcasting operator. The broadcasting equipment 20 constitutes the broadcasting equipment used to provide broadcasting services. In broadcasting services, broadcasting content is provided using a broadcasting network. Broadcasting content is typically composed of a package containing multiple components. These components may include some or all of the audio data, video data, and data broadcasting content of the broadcast program.

[0016] The broadcasting device 20 includes a data compilation unit, a multiplexing unit, and a transmission unit (not shown). The data compilation unit acquires a package that constitutes the broadcast content and control information related to the transmission of the package. The package contains multiple components. In this application, video and audio are mainly given as examples of components. A component containing video data may be called a video component, and a component containing audio data may be called an audio component. The package may also contain components containing materials of different types, such as subtitles. The package may contain either video or audio, and not the other. The broadcast content is encrypted using a predetermined encryption method (e.g., AES (Advanced Encryption Standard), Camellia, etc.). In the following description, encrypted broadcast content may be referred to as "encrypted content." The broadcasting device 20 may further include an encryption unit. The encryption unit encrypts the plaintext broadcast content and converts it into encrypted content.

[0017] The multiplexing unit multiplexes encrypted content and control information using a predetermined data multiplexing scheme to generate multiplexed data. The transmission unit encodes the generated multiplexed data and modulates the encoded multiplexed data using a predetermined modulation scheme. The transmission unit converts the baseband broadcast signal obtained by modulation into a broadcast signal in the frequency band corresponding to a predetermined channel and transmits the converted broadcast signal to the broadcast network. Examples of multiplexing schemes used include the MPEG-2 TS (Transport Stream) scheme and the MMT-TLV (MPEG Media Transport-Type Length Value) scheme.

[0018] The individual components that make up broadcast content are also called Elementary Streams (ES) or assets. In this application, the term "component" is primarily used. In this application, sending data over a broadcast transmission line is sometimes referred to as "transmitting by broadcast," and receiving various data transmitted over a broadcast transmission line is sometimes referred to as "receiving by broadcast."

[0019] Control information may include information on the provision of broadcast services as well as notification information indicating downloads. Broadcast downloads correspond to in-receiver information update services. Notification information describes information such as the download data to be transmitted, the channel used for transmission, and the schedule (transmission period). In this embodiment, the CAS program to be updated is transmitted as download data. The download of the CAS program is provided as part of the engineering service. Notification information is common to all broadcast transmission lines provided in that area. When the MPEG-2 TS method is used as the multiplexing method, notification information is described in SDTT (described later) using a common transport stream (all-station TS) for all broadcasting stations or channels and transmitted. SDTT is transmitted at predetermined transmission cycles (e.g., every 180 seconds).

[0020] The channel on which the CAS program is transmitted may differ from the channel on which the broadcast service is provided. Furthermore, the broadcasting equipment 20 that transmits broadcast content may be separate from the broadcasting equipment that transmits the CAS program. Examples of notification information will be discussed later. Note that while Figure 1 shows one receiving device 10 and one broadcasting device 20, the number of receiving devices 10 can generally be unspecified and multiple. Similarly, the number of broadcasting devices 20 can also be multiple.

[0021] Next, an example of the functional configuration of the receiving device 10 according to this embodiment will be described. The receiving device 10 is composed of an operation input unit 102, a station selection processing unit 104, a receiving processing unit 110, a software update unit 122, a CAS processing unit 124, and an output processing unit 130. The receiving device 10 may have a computer system. The computer system has a processor such as a CPU (Central Processing Unit) that executes a predetermined program, and works in cooperation with a storage medium such as RAM (Random Access Memory) and other hardware to realize the functions of the receiving device 10.

[0022] The functions of the station selection processing unit 104, the reception processing unit 110, the software update unit 122, and the output processing unit 130 may be implemented by the main computer system of the receiving device 10 executing a predetermined control program, or they may be implemented using dedicated hardware. The CAS processing unit 124 may include a dedicated integrated circuit (IC). This integrated circuit executes the CAS program set by the software update unit 122 to realize its functions. In this application, the execution of processes instructed by commands written in various programs, including application programs and browsers, may be referred to as "program execution" or "executing a program."

[0023] The operation input unit 102 acquires an operation signal indicating the channel selected by the user and outputs the acquired operation signal to the channel selection processing unit 104. In this application, the selected channel may be referred to as the "selected channel". The operation input unit 102 includes a receiver that receives the operation signal from a control device (e.g., a remote controller) via wired or wireless connection. The operation signal is output by the control device after it receives the user's operation (S02: channel selection operation).

[0024] The operation input unit 102 may include components that accept user operations (e.g., buttons, dials, levers, etc.) and output an operation signal generated based on the accepted operation to the station selection processing unit 104. The channel selection processing unit 104 identifies the information indicated by the operation signal input from the operation input unit 102 and detects the channel selection information from the identified information. The channel selection processing unit 104 notifies the receiving processing unit 110 of the detected channel selection information.

[0025] The receiving processing unit 110 acquires broadcast content from the received signal transmitted via broadcast waves. The receiving processing unit 110 comprises a broadcast receiving unit 112 and a broadcast decoding unit 114. The broadcast receiving unit 112 receives a received signal obtained by receiving broadcast waves transmitted on the selected channel notified by the channel selection processing unit 104. The broadcast receiving unit 112 includes, for example, a tuner (not shown). The tuner extracts a signal indicating the frequency component that tunes to the frequency of the selected channel from the received signal, which is input directly or indirectly from an antenna (not shown), as a tuning signal. The tuner converts the extracted tuning signal into a baseband received signal and outputs the converted received signal to the broadcast decoding unit 114 (S04: channel selection process). The antenna outputs an electrical signal obtained by receiving broadcast waves arriving at its unit as a received signal to the tuner. The antenna may be included as part of the receiving device 10, or it may be a separate unit from the receiving device 10.

[0026] The broadcast decoding unit 114 demodulates the received signal input from the broadcast receiving unit 112 using a predetermined demodulation method and converts it into encoded multiplexed data. The demodulation method corresponds to the modulation method used to modulate the multiplexed data. The broadcast decoding unit 114 decodes the multiplexed data obtained by the conversion using a predetermined decoding method (S06: broadcast decoding). The decoding method corresponds to the encoding method used to encode the multiplexed data.

[0027] The broadcast decoding unit 114 separates control information related to the transmission of the broadcast content package from the decoded multiplexed data. Based on the separated control information, the broadcast decoding unit 114 extracts the components that make up the broadcast content from the multiplexed data. Multiplexed data may be transmitted with a scramble control flag (also called a scramble flag) attached. The scramble control flag indicates whether or not the broadcast content is encrypted (scrambled). In other words, the scramble control flag can also be considered an information flag that indicates whether the broadcast content transmitted in the multiplexed data is encrypted content or plaintext broadcast content. For example, the broadcast decoding unit 114 determines whether or not to decode (descramble) the broadcast content based on whether or not the scramble flag is encrypted (S08: Decoding necessity determination).

[0028] When the broadcast decoding unit 114 determines that decoding is required, it extracts limited reception support information from the control information to support limited reception. The limited reception support information includes individual information and common information (described later). The broadcast decoding unit 114 outputs the extracted individual information and common information to the CAS processing unit 124. The CAS processing unit 124 obtains a decryption key (descramble key) from the individual and common information input from the broadcast decoding unit 114 according to the CAS program (S10: Decryption key acquisition). The CAS processing unit 124 returns the decryption key obtained by decryption to the broadcast decoding unit 114. The broadcast decoding unit 114 decrypts the encrypted content transmitted as multiplexed data using the decryption key input from the CAS processing unit 124 and converts it into plaintext broadcast content (S12: Content Decryption (Descramble)). Furthermore, when determining whether or not to decode based on the scramble control flag, the broadcast decoding unit 114 determines that the extracted broadcast content is in plain text. The broadcast decoding unit 114 outputs the video and audio components that make up the plain text broadcast content to the output processing unit 130.

[0029] The control information may include notification information. When the broadcast decoding unit 114 detects notification information from the multiplexed data, it outputs the detected notification information to the software update unit 122. The notification information includes information indicating the channel, schedule, and data to be transmitted for the download data. The notification information may include a CAS program ID indicating the transmission of a CAS program.

[0030] When the software update unit 122 detects a CAS program ID from the notification information, it causes the receiving processing unit 110 to receive the CAS program transmitted during the notified time period using the channel notified in the notification information (S16: CAS program acquisition). The receiving processing unit 110 uses the channel instructed by the software update unit 122 and receives the received signal in the background at some point during the instructed time period. That is, the reception time of the CAS program is different from the reception time of the broadcast content. Also, the reception channel of the CAS program may be different from the reception channel of the broadcast content. The broadcast decoding unit 114 outputs the CAS program, which is transmitted as download data from the multiplexed data obtained by demodulating and decoding the received signal, to the software update unit 122.

[0031] The software update unit 122 includes a software information storage unit 122s. The software information storage unit 122s stores receiver software information and various software. The receiver software information includes version information for individual software. The software stored in the software information storage unit 122s may include the CAS program. The receiver software information includes version information for the CAS program stored at that time. The software information storage unit 122s is configured to include non-volatile memory such as flash ROM (Read-Only Memory). The software update unit 122 determines whether the version of the CAS program obtained from the broadcast decoding unit 114 is newer than the version stored in its unit. The software update unit 122 stores the newer version of the CAS program determined to be newer in the software information storage unit 122s and updates the existing version indicated in the receiver software information to the new version. The software update unit 122 sets the newly obtained version of the CAS program in the CAS processing unit 124 (S18: CAS program update).

[0032] The output processing unit 130 performs processing to output components acquired by broadcast or communication. The output processing unit 130 includes a video decoding unit 132 and an audio decoding unit 134. The video decoding unit 132 performs decoding on the video data constituting the video components input from the broadcast decoding unit 114 using a predetermined video decoding method (S14: video decoding). The video decoding method can be any method that corresponds to the video encoding method used to encode the video data (for example, MPEG2 VIDEO, HEVC: High Efficient Video Coding, VVC: Versatile Video Coding, etc.). The output processing unit 130 outputs display screen data including the video data obtained by the video decoding process to a display (not shown) (video output). The display shows a display screen of a broadcast program including video based on the decoded video data.

[0033] The audio decoding unit 134 performs decoding on the audio data constituting the audio components input from the broadcast decoding unit 114 using a predetermined audio decoding method (S14: audio decoding). The audio decoding method can be any method that corresponds to the audio encoding method used to encode the audio data (for example, MPEG-2 AAC, MPEG-4 Audio, etc.). The output processing unit 130 outputs the audio data obtained by the audio decoding process to a speaker (not shown) (audio output). The speaker emits sound based on the decoded audio data.

[0034] The display, which is the output destination for video data, and the speaker, which is the output destination for audio data, or one or both, may be provided on the receiving device 10, or they may be separate from the receiving device 10. The output destinations for video data and audio data are not limited to the display and speaker, respectively, but may also be a recording device (for example, a video recorder).

[0035] Furthermore, when the MPEG-2 TS format is used as the multiplexing method, the broadcast decoding unit 114 extracts a PSI (Program Specific Information) table representing control information from the multiplexed data. The PSI table includes information tables related to the provision of broadcast services. Such information tables include, for example, PAT, NIT, PMT, and CAT.

[0036] The broadcast decoding unit 114 extracts the Program Association Table (PAT) from the PSI table and identifies the packet ID (PID) of the packets (TS packets) that constitute the transport stream transmitting the Program Map Table (PMT, described later) described in the PAT. A scramble control flag may be written in the header of the TS packet. The PAT is an information table that specifies the PID of the TS packet that transmits the PMT related to the broadcast program. The PMT is an information table that specifies the PID of the TS packet that transmits the broadcast content.

[0037] The broadcast decoding unit 114 extracts the PMT described in the identified PID and identifies the elementary stream packet identifier (elementary_PID) associated with the video stream format identifier (stream_type, e.g., 0x01) from the extracted PMT. The broadcast decoding unit 114 extracts the elementary stream (ES) containing packets with the identified PID attached from the multiplexed data as the video component. The broadcast decoding unit 114 also identifies the PID associated with the audio stream format identifier (e.g., 0x0F) from the PMT. The broadcast decoding unit 114 extracts the elementary stream containing PES (Packetized Elementary Stream) packets with the identified PID attached from the multiplexed data as the audio component. The PES packets and control information are stored in the payload of the TS packets. One PES packet is divided and stored in one TS packet or in multiple TS packets with a common PID. The extracted video and audio components may be encrypted or remain unencrypted in plain text. Encrypted video and audio components constitute encrypted content. The encrypted content is converted back into plain text in the broadcast decoding unit 114 using the decryption key decrypted in the CAS processing unit 124 as described above.

[0038] The broadcast decoding unit 114 extracts a Conditional Access Table (CAT) from the PSI table. The CAT contains conditional access support information to support conditional access. The CAT transmits information about the TS that transmits individual information. The information supporting conditional access includes individual information and common information. The individual information includes contract information for each recipient and key information (work key) for decrypting the common information. The individual information is described in the Entitlement Management Message (EMM). The common information is encrypted in advance using the work key. The common information includes key information (descramble key, equivalent to the decryption key above) for decrypting and decrypting the encrypted content. The encrypted common information is described in the Entitlement Control Message (ECM). The broadcast decoding unit 114 outputs the individual information extracted from the CAT and the encrypted common information to the CAS processing unit 124. The CAS processing unit 124 performs the following processing according to the CAS program set in its unit to obtain a descramble key from the individual information and common information (S10: Decryption key acquisition). (i) Extract the work key from the individual information input from the broadcast decoding unit 114. (ii) The CAS processing unit 124 decrypts the encrypted common information using the work key and extracts the descramble key from the decrypted common information. (iii) The CAS processing unit 124 outputs the extracted descramble key to the broadcast decoding unit 114. The broadcast decoding unit 114 then decrypts the encrypted content using the descramble key input from the CAS processing unit 124.

[0039] The control information may include notification information. This notification information is described in the Software Download Trigger Table (SDTT). When the broadcast decoding unit 114 detects an SDTT in the multiplexed data, it extracts the SDTT from the multiplexed data and outputs the extracted SDTT to the software update unit 122.

[0040] Next, an example of the configuration of the software update unit 122 according to this embodiment will be described. Figure 2 is a schematic block diagram showing an example of the configuration of the software update unit 122 according to this embodiment. The software update unit 122 is comprised of a software information storage unit 122s, an update processing unit 122u, and a verification processing unit 122c.

[0041] The software information storage unit 122s stores receiver software information and various types of software. The receiver software information includes the manufacturer ID, model number, group number, and version information of the receiver 10. The manufacturer ID is identification information indicating the manufacturer of the receiver 10. The model number is a number indicating the model of the receiver 10. The version information indicates the version number of each software. The group number indicates the type of each software. The program type may differ for each CAS module that makes up the CAS processing unit 124. The group number may differ depending on the manufacturer of the CAS module. A memory bank is set up in a portion of the storage area of ​​the software information storage unit 122s. Various types of data are stored in the memory bank. The memory bank may also include a memory bank dedicated to downloaded data. Software for the receiving device 10, such as the CAS program, is stored in the memory bank.

[0042] The update processing unit 122u obtains a newer version of the CAS program than the existing version from the receiving processing unit 110 based on the notification information described in the SDTT notified by the broadcast decoding unit 114. The verification processing unit 122c performs error detection on the bit sequence representing the acquired CAS program to determine if the acquired downloaded data corresponds to the CAS program notified in the notification information. If an error is detected, it causes the update processing unit 122u to acquire the CAS program again. The update processing unit 122u stores CAS programs for which no errors are detected in the software information storage unit 122s, sets them in the CAS processing unit 124, and updates the receiver software information.

[0043] Next, the CAS program update process according to this embodiment will be described using Figures 2 and 3. Figure 3 is a flowchart of the CAS program update process according to this embodiment. (Step S22) The update processing unit 122u receives SDTT from the broadcast decoding unit 114. (Step S24) The update processing unit 122u reads the receiver software information from the software information storage unit 122s.

[0044] (Step S26) The update processing unit 122u determines whether or not to download the CAS program based on the notification information and receiver software information described in the SDTT. Here, the update processing unit 122u determines that if the notification information does not include CAS program information, it does not need to download the CAS program.

[0045] If the notification information includes CAS program information, the update processing unit 122u identifies the version of the existing CAS program to be updated (which may be referred to as the "target version" or "target version" in the following description) and the version of the new CAS program after the update (which may be referred to as the "new version" in the following description) from the notification information. The update processing unit 122u compares the identified new version and target version with the version of the existing CAS program shown in the receiver software information (which may be referred to as the "existing version" in the following description). If the existing version matches the target version and the new version is different from the target version, the update processing unit 122u determines that the CAS program needs to be downloaded. Otherwise, the update processing unit 122u determines that the CAS program does not need to be downloaded. If the update processing unit 122u determines that a download is required (step S26 Download Required), it proceeds to step S28. If the update processing unit 122u determines that a download is not required (step S26 No Download), it terminates the process shown in Figure 3.

[0046] (Step S28) The update processing unit 122u determines whether or not a forced download is instructed in the notification information. If an optional download is instructed, it displays a predetermined selection screen on the display. The selection screen consists of the download content, i.e., information of the CAS program to be transmitted, and screen components (i.e., UI components) for selecting whether or not to download according to the operation. When the update processing unit 122u receives an operation signal from the operation input unit 102 indicating that a download is required, it sets a timer with the transmission start time notified by SDTT as the activation time. After that, it proceeds to the process in step S30. When the update processing unit 122u receives an operation signal from the operation input unit 102 indicating that a download is not required, it terminates the process shown in Figure 3. If a forced download is instructed, the update processing unit 122u sets a timer using the start time notified by SDTT as the activation time without displaying a selection screen. Then, it proceeds to the process in step S30.

[0047] (Step S30) When the update processing unit 122u receives an operation signal from the operation input unit 102 indicating power off (OFF) in response to an operation, it changes the state of the receiving device 10 from the normal operating state to standby state 1. In standby state 1, the main power supply of the receiving device 10 is turned on, and the sub-power supply is turned off (OFF). Even when the sub-power supply is turned off, certain limited functions such as power control and timer operation are realized, but functions related to the provision of broadcast services, such as broadcast signal reception processing and broadcast content output processing, are stopped. In contrast, in the normal operating state, the functions related to the provision of broadcast services, which are the main functions of the receiving device 10, are realized.

[0048] In standby state 1, the update processing unit 122u waits until the current time becomes the start time set on the timer. When the current time becomes the start time, the update processing unit 122u changes the state of the receiving device 10 from standby state 1 to standby state 2. In standby state 2, the receiving device 10 implements functions related to software download in addition to the functions implemented in standby state 1. At this time, the update processing unit 122u outputs a start command to the receiving processing unit 110, which starts the receiving processing unit 110 and begins receiving broadcast signals carried by broadcast waves using the channels described in SDTT. In standby state 2, the auxiliary power supply remains off, and functions related to broadcast services are not implemented. In other words, the software download is performed in the background. The process then proceeds to step S32.

[0049] Furthermore, when the receiving device 10 is in standby state 1 or standby state 2, the update processing unit 122u changes the state of the receiving device 10 to the normal operating state when an operation signal indicating power supply (ON) is input from the operation input unit 102 in response to an operation. The broadcasting device 20 transmits the CAS program as download data using the notified channel during the transmission period notified by SDTT.

[0050] In the transmission of downloaded data, for example, the DSM-CC (Digital Storage Media Command and Control) data carousel method may be used as a protocol specified in ISO / IEC 13818-6. The DSM-CC data carousel method is a method that repeatedly transmits data blocks containing the data to be transmitted. The transmission of receiver software (including the CAS program) using the data carousel method is part of the engineering service. Downloaded data may be divided into multiple data blocks so that the amount of information is below a predetermined upper limit. Each data block is modularized and transported in a DDB (Download Data Block) message. Information about the downloaded data is described in a DII (Download Info Indication) message. In the following description, DDB messages and DII messages may be simply referred to as "DDB" and "DII," respectively.

[0051] The multiplexing unit of the broadcasting device 20 generates a transport stream containing a DII and one or more DDBs as multiplexed data related to the downloaded data. The generated transport stream is assigned the transport stream ID notified in the notification information. The transmitting unit of the broadcasting device 20 starts transmitting the configured transport stream at the start time notified in the notification information to the broadcasting transmission path specified by the notified transmission channel during the transmission period notified in the notification information (DSM-CC data carousel).

[0052] On the other hand, the broadcast decoding unit 114 of the receiving device 10 extracts the DII and DDB from the multiplexed data obtained by demodulating and decoding the received signal. The broadcast decoding unit 114 sequentially outputs the acquired DII and DDB to the software update unit 122. The update processing unit 122u of the software update unit 122 receives the DII from the broadcast decoding unit 114 (DII acquisition). The update processing unit 122u identifies the download identification included in the download information described in the acquired DII.

[0053] (Step S32) The update processing unit 122u compares the download identification identified from the DII with the download identification notified by SDTT and determines whether the two match. If the two do not match (Step S32 No download required), the update processing unit 122u terminates the process shown in Figure 3. If the two match, the process proceeds to Step S34. If the download identification identified from the DII does not match the download identification notified by SDTT, the process in step S32 may be repeated until a matching DII is obtained.

[0054] (Step S34) The update processing unit 122u compares the model and version included in the download information with the model and version notified by SDTT and determines whether they are equal. This confirms whether the transmitted download data corresponds to the download data notified in the notification information. If they are not determined to be equal (Step S34 No download required), the update processing unit 122u terminates the process shown in Figure 3. If they are determined to be equal (Step S34 Download required), the process proceeds to Step S36.

[0055] (Step S36) The update processing unit 122u receives a DDB message from the broadcast decoding unit 114 (DDB acquisition). (Step S38) The update processing unit 122u extracts the data blocks of the CAS program stored in the acquired DDB message and expands the extracted data blocks into the working memory (e.g., RAM) of the verification processing unit 122c. If the CAS program to be transmitted is divided into multiple DDB messages, the update processing unit 122u sequentially expands the data blocks extracted from each DDB message into adjacent storage areas of the working memory (e.g., RAM) of the verification processing unit 122c. The CAS program is reconstructed by sequentially connecting the divided data blocks. The verification processing unit 122c performs a predetermined error detection process (for example, CRC (Cyclic Redundancy Check)) on the CAS program obtained from the update processing unit 122u, determines whether or not an error has occurred in the bit sequence constituting the CAS program, and notifies the update processing unit 122u of the detection result. If the update processing unit 122u detects an error, it returns to the process in step S36. If the update processing unit 122u does not detect an error, it proceeds to the process in step S40.

[0056] (Step S40) The update processing unit 122u reads the CAS program that has been loaded into the working memory of the verification processing unit 122c, and stores the read CAS program in the download-only memory bank of the software information storage unit 122s. Then, the process proceeds to step S42. (Step S42) The update processing unit 122u replaces the version of the CAS program indicated in the receiver software information with the version of the CAS program newly stored in the software information storage unit 122s. The update processing unit 122u updates the existing receiver software information with receiver software information indicating the latest version of the CAS program and saves it in the software information storage unit 122s.

[0057] (Step S44) The update processing unit 122u sets a startup flag in the download-only memory bank where the CAS program is stored. This indicates that the newly stored CAS program is to be started as the software to be started. (Step S46) When a restart is instructed by notification information, the update processing unit 122u restarts. Whether or not a restart is necessary is indicated by a restart flag in the SDTT download content description. The timing and scope of the restart depend on the configuration and software of the receiving device 10. The update processing unit 122u, for example, starts the operation of the CAS processing unit 124 and installs the CAS program newly stored in the software information storage unit 122s into the CAS processing unit 124 (reset / CAS program update). After that, the process shown in Figure 3 is terminated.

[0058] Next, an example of the SDTT data structure will be described. SDTT is a data table used for notifying users of download information for software, etc. The data organization unit of the broadcasting device 20 acquires notification information related to the transmission of CAS programs. The notification information includes the version of the CAS program to be transmitted, the version of the CAS program to be updated, the transmission period, and information about the channel to be used as the transmission path. The data organization unit generates an SDTT that shows the acquired notification information. The data multiplexing unit of the broadcasting device 20 generates multiplexed data that includes the SDTT as part of the control information.

[0059] Figure 4 shows an example of the data structure of SDTT. SDTT consists of fields including table identifier (table_id), table identifier extension (table_id_ext), transport stream ID (transport_stream_id), original network ID (original_network_id), service ID (service_id), group (group), target version (target_version), new version (new_version), download level (download_level), schedule description length (schedule_description_length), start time (start_time), duration (duration), and descriptors (descriptors()).

[0060] In the table identification column, the value "0xC3" is written as the value indicating SDTT. The broadcast decoding unit 114 identifies the data table in the received signal that has "0xC3" written as the table identification value as the SDTT. The table identification extension field contains a value indicating the type of download data to be downloaded. The value of the table identification extension (table_id_ext) is assigned as exemplified in Figure 5. For CAS program information indicating the transmission of the CAS program as data common to all receivers, "0xFFF1" is assigned. The tuning processing unit 104 can identify an SDTT with "0xFFF1" as the value of the table identification extension as an SDTT containing CAS program information indicating the download of a CAS program transmitted as data common to all receivers.

[0061] CAS program information may be notified using a value other than "0xFFF1". For example, CAS program information may be notified using a value from the set of manufacturer identifier maker_id and model identifier model_id that is not assigned to any manufacturer or model. In the example in Figure 5, any value from "0x0000" to "0xDFFF" may be assigned to the CAS program information.

[0062] The set of the original network ID (original_network_id) or transport stream ID (transport_stream_id) and service ID (service_id) indicates the channel through which the downloaded data is transmitted. Typically, the same value is set for both the original network ID (original_network_id) and the transport stream ID (transport_stream_id). In that case, the update processing unit 122u can identify the channel through which the CAS program is transmitted based on the value of either the original network ID (original_network_id) or the transport stream ID (transport_stream_id) and the service ID (service_id) from the SDTT.

[0063] The group indicates the type of software. The target version indicates the version of the software to be updated. The new version indicates the new software version to be transmitted. In this embodiment, a CAS program identifier (CA_program_ID) is transmitted, which identifies each CAS program by a set of group and version. In the example in Figure 6, the CAS program identifier has a length of, for example, 13 bits. The lower 12 bits of the CAS program identifier indicate the version of the CAS program, which represents the target version or new version. The higher bits of the CAS program identifier indicate the type of CAS program, i.e., the group. The receiver software information may include a CAS program identifier indicating the type and version of the CAS program currently in use, as group number and version information related to the CAS program.

[0064] The download level (download_level) indicates whether the download being notified is a mandatory download or an optional download. The schedule description length (schedule_description_length) indicates the byte length of the schedule loop. However, if the value of the schedule description length is zero, it indicates that the download content to be transmitted will be transmitted as common data for all receivers. The broadcasting device 20 is operated to transmit the common data for all receivers at least once within 20 minutes.

[0065] The update processing unit 122u can determine whether the type of CAS program installed on its device is likely to be subject to update by checking whether the group value described in the SDTT is the same as the group number described in the receiver software information. The update processing unit 122u can identify the version of the CAS program to be updated and the version of the CAS program to be transmitted, based on the value of the target version (target_version) and the value of the new version (new_version).

[0066] The start time (start_time) and duration (duration) indicate the transmission period of the downloaded data. The start time (start_time) indicates the start time of the transmission period. The duration (duration) indicates the period from the start time to the end time of the transmission period. The update processing unit 122u can identify the transmission period of the CAS program to be updated based on the start time (start_time) value and the duration (duration) value.

[0067] The descriptors() field contains various descriptors. For example, the download content descriptor (download_content_descriptor) is described in the descriptors() field. The download content descriptor (download_content_descriptor) includes fields for download ID (Download_id) and reboot flag (Reboot). The download ID (Download_id) is an identifier used to identify the download of individual software. The reboot flag (Reboot) is an information flag indicating whether a reboot is necessary.

[0068] Next, we will describe an example of the DII data structure. Figure 7 shows an example of the DII data structure. The DII consists of fields for download identification (downloadId), compatibility descriptor, and module. The same value as the download identification notified in the notification information is described as the download identification. The update processing unit 122u can refer to the download identification notified in the notification information to identify the DII related to the transmission of the corresponding download data.

[0069] The module section includes a field for the number of modules (numberOfmodules), and for each module, fields for module ID (moduleID), module size (ModuleSize), module version (moduleVersion), module information length (moduleInfoLength), and module information (moduleInfoByte). The number of modules refers to the number of modules that contain some or all of the downloaded data. In this embodiment, each module is composed of segments from which the CAS program has been divided. The module ID is the identification number of each individual module. The module size is described as the number of bytes that represent the amount of information contained in each individual module. The version of each individual module is described as the module version.

[0070] The module information length is described as the number of bytes that indicate the amount of information in the subsequent module information. Module information provides more detailed information than individual modules. The update processing unit 122u can identify the DDB containing the module involved in the transmission of downloaded data by referring to the module ID.

[0071] The compatibility descriptor (compatibilityDescriptor()) describes the model and version of the software to be transmitted. In this embodiment, as illustrated in Figure 8, the CAS program information transmitted using the table ID extension (table_id_ext) of the notification information is described in the model field. Here, the value of the CAS program information, "0xFFF1", is described in the 16-bit area allocated to the model field. In addition, the CAS program identifier (CA_Program_ID) notified in the notification information is described in the version field. A 13-bit value is described as the CAS program identifier (CA_Program_ID) in the 16-bit area allocated to the version field.

[0072] Therefore, the update processing unit 122u can determine whether the DII containing the compatibility descriptor relates to the transmission of a CAS program by checking whether the value described in the model field of the compatibility descriptor (compatibilityDescriptor()) is equal to the value "0xFFF1" in the CAS program information. Furthermore, the update processing unit 122u can determine whether the DII containing the compatibility descriptor relates to the transmission of a CAS program of the type and version indicated by the CAS program identifier (CA_Program_ID) by checking whether the value described in the model field of the compatibility descriptor (compatibilityDescriptor()) is equal to the CAS program identifier (CA_Program_ID) notified in the notification information.

[0073] Part or all of the CAS program body to be transmitted is described in the DDB in association with a CAS program identifier. Each DDB contains the CAS program body described using a CAS program descriptor (CasProgramInformation()) as illustrated in Figure 9. The CAS program descriptor (CasProgramInformation()) includes fields for the CAS program identifier (CA_Program_ID), module length (module_length), and description area (moduleDataByte). The module length (module_length) is the number of bytes indicating the amount of information in the CAS program described in the description area (moduleDataByte). The description area (moduleDataByte) contains part or the entirety of the CAS program body.

[0074] Next, an example of the download reservation process according to this embodiment will be described. Figure 10 is a flowchart illustrating the download reservation process according to this embodiment. The process in Figure 10 constitutes part of the procedure from step S22 to step S28 in Figure 3. (Step S102) The channel selection processing unit 104 identifies the channel selected by the user from the operation signal input from the operation input unit 102 and notifies the broadcast receiving unit 112 of the identified channel. The broadcast receiving unit 112 receives the received signal transmitted on the broadcast wave of the notified channel. The broadcast decoding unit 114 demodulates the received signal and obtains a TS packet to store the demodulated and multiplexed data.

[0075] (Step S104) The broadcast decoding unit 114 determines whether the value of the packet ID (PID) written in the header of the acquired TS packet is "0x28". If it is "0x28" (Step S104 YES), the process proceeds to step S106. If it is not "0x28" (Step S104 NO), the process of step S104 is repeated. (Step S106) The broadcast decoding unit 114 determines whether the value of the table identifier (table_id) of the data table stored in the TS packet is "0xC3". If it is "0xC3" (Step S106 YES), the process proceeds to step S108. Through the processes of steps S104 and S106, the SDTT is detected from the multiplexed data. The broadcast decoding unit 114 outputs the detected SDTT to the software update unit 122. If the value of the table identifier (table_id) is not "0xC3" (Step S106 NO), the process returns to step S104.

[0076] (Step S108) The update processing unit 122u of the software update unit 122 determines whether the value of the table identification extension (table_id_ext) described in the SDTT input from the broadcast decoding unit 114 is "0xFFF1". If it is "0xFFF1" (Step S108 YES), the process proceeds to step S110. This value indicates CAS program information, and the notification information described in the SDTT indicates that the CAS program is to be downloaded. If the value of the table identification extension (table_id_ext) is not "0xFFF1" (Step S108 NO), the process returns to step S104.

[0077] (Step S110) The update processing unit 122u reads the receiver software information from the software information storage unit 122s. The update processing unit 122u determines whether the CAS program version has been updated based on the CAS program identifier described in the SDTT and the CAS program identifier described in the receiver software information. More specifically, the update processing unit 122u compares the CAS program identifier described in the model and target version fields of the SDTT with the CAS program identifier described in the receiver software information, and determines whether the CAS program of the device is subject to update based on whether the two are equal. If the device is subject to update, the update processing unit 122u determines whether the new version described in the SDTT is newer than the target version. If the CAS program of the device is subject to update and the new version is newer than the target version, the update processing unit 122u can determine that the version has been updated. If it is determined that the version has been updated (Step S110 YES), the process proceeds to step S112. If it is determined that the version has not been updated (Step S110 NO), the process returns to step S104.

[0078] (Step S112) The update processing unit 122u sets a download reservation for the CAS program. More specifically, the update processing unit 122u identifies the channel on which the engineering service is provided as the channel on which the download is scheduled, based on the transport stream ID or the set of original network ID and service ID described in the SDTT. The update processing unit 122u identifies the start time described in the SDTT as the activation time. The update processing unit 122u determines that the CAS program will be transmitted as common data for all receivers when the value of the schedule description length described in the SDTT is "0". After that, the process shown in Figure 10 is terminated.

[0079] Next, an example of the process for initiating the download of the CAS program according to this embodiment will be described. Figure 11 is a flowchart illustrating the process for initiating the download of the CAS program according to this embodiment. The process in Figure 11 is part of the procedure from step S28 to step S36 in Figure 3.

[0080] (Step S202) When the update processing unit 122u detects a predetermined trigger, it activates the configured download reservation. The update processing unit 122u detects, for example, an operation signal input from the operation input unit 102 indicating a power outage as a trigger. The update processing unit 122u changes the state of the receiving device 10 from the operating state to the standby state 2 and sets a timer to start receiving the received signal on the channel specified at the start time set in the download reservation. (Step S204) When the current time becomes the startup time, the update processing unit 122u selects the channel to provide engineering services and starts background reception on that channel. More specifically, the update processing unit 122u changes the state of the receiving device 10 from standby state 2 to standby state 1 and instructs the receiving processing unit 110 to start receiving, demodulating, and decoding the received signal on the channel set in the download reservation.

[0081] (Step S206) The broadcast decoding unit 114 demodulates and decodes the received signal received by the broadcast receiving unit 112 on the channel providing engineering services, and converts it into multiplexed data. The broadcast decoding unit 114 obtains the DII from the converted multiplexed data and outputs the obtained DII to the update processing unit 122u. (Step S208) The update processing unit 122u determines whether the values ​​described in the model and version fields of the compatibility descriptor of the DII input from the broadcast decoding unit 114 are equal to "0xFFF1", which is a value indicating CAS program information. If they are determined to be equal (Step S208 YES), the process proceeds to step S210. At this time, the DII is shown as CAS program download information. If they are determined to be not equal (Step S208 NO), the process returns to step S206. (Step S210) The update processing unit 122u reads the download identification from the DII.

[0082] (Step S212) The broadcast decoding unit 114 obtains the DDB from the multiplexed data obtained from the received signal received on the channel providing the above engineering service, and outputs the obtained DDB to the update processing unit 122u. (Step S214) The update processing unit 122u reads the download identification from the DDB input from the broadcast decoding unit 114 and determines whether the download identification read from the DDB is equal to the download identification read from the DII. If they are determined to be equal (Step S214 YES), the process proceeds to step S216. If they are determined to be not equal (Step S214 NO), the process returns to step S212.

[0083] (Step S216) The update processing unit 122u reads the CAS program stored in the DDB. If a module containing a single CAS program is stored across multiple DDBs, the update processing unit 122u reads the module from each DDB and reconstructs the CAS program by combining the read modules. After that, the process shown in Figure 11 is terminated.

[0084] As described above, the receiving device 10 according to this embodiment includes a receiving processing unit 110 that decrypts encrypted content from a received signal obtained by receiving a broadcast wave, a limited receiving processing unit (e.g., CAS processing unit 124) that obtains a decryption key for decrypting the content acquired according to a limited receiving processing program (e.g., CAS program), an output processing unit 130 that outputs the decrypted content, and a software update unit 122. The receiving processing unit 110 detects notification information regarding the transmission of download data from the received signal, and the software update unit 122, when the notification information contains limited receiving processing program information (e.g., CAS program information) regarding the transmission of a limited receiving processing program, acquires a limited receiving processing program during the transmission period notified by the notification information and sets the acquired limited receiving processing program in the limited receiving processing unit. The receiving processing unit 110 may, for example, detect limited receiving processing program information based on the table identification extension (table_id_ext) described in the SDTT. The receiving processing unit 110 may, for example, detect limited receiving processing program information based on the manufacturer identification (maker_id) and model identification (model_id) described in the SDTT. According to this configuration, based on the restricted reception processing program information described in the notification information, the transmission of the restricted reception processing program is notified, and the restricted reception processing program is acquired during the transmission period notified in the notification information. Therefore, it is possible to acquire the updated restricted reception processing program using hardware similar to that used for downloading existing software. In other words, by supporting updates to the restricted reception processing program without requiring hardware changes, the protection of broadcast content is enhanced.

[0085] The notification information indicates the channel on which the limited reception processing program is transmitted, and the reception processing unit 110 may receive the reception signal on that channel. In this configuration, a limited reception processing program is obtained from the received signal received on the channel notified in the announcement information.

[0086] The notification information indicates the version of the limited reception processing program (e.g., target version, new version), and the software update unit 122 determines whether or not to receive the limited reception processing program based on that version. This configuration allows you to avoid receiving data from unnecessary limited reception programs, such as existing versions of limited reception programs or older versions of limited reception programs.

[0087] The software update unit 122 reserves the reception of the limited reception processing program when it does not output the decrypted content (for example, in standby mode). In this configuration, when no broadcast content is being output, the reception of the limited reception processing program is reserved. As a result, the limited reception processing program is updated without the viewer noticing.

[0088] Next, the differences between the second embodiment of the present application and the above-described embodiment will be explained primarily. Unless otherwise specified, the similarities with the above-described embodiment will be explained by referring to the above-described embodiment. Figure 12 is a schematic block diagram showing an example of the functional configuration of the broadcasting system S2 according to this embodiment. The broadcasting system S2 comprises a receiving device 10 and broadcasting devices 20a, 20b, and 20c. Broadcasting devices 20a, 20b, and 20c each have a configuration similar to that of the broadcasting device 20 in Figure 1. That is, broadcasting devices 20a, 20b, and 20c each acquire broadcasting content and control information related to the transmission of the broadcasting content. Broadcasting devices 20a, 20b, and 20c each multiplex the acquired broadcasting content and control information to generate multiplexed data, and then encode and modulate the generated multiplexed data to convert it into a broadcast signal. Broadcasting devices 20a, 20b, and 20c each transmit the broadcast signal via broadcast.

[0089] However, broadcasting equipment 20a, 20b, and 20c will provide terrestrial digital broadcasting, BS (Broadcasting Satellite) digital broadcasting, and CS (Communication Satellite) digital broadcasting, respectively. Terrestrial digital broadcasting is provided using terrestrial waves, which carry the broadcast signal, as the transmission path. The broadcasting equipment 20a transmits the broadcast signal to the radio wave transmission equipment, and the radio wave transmission equipment transmits broadcast waves (terrestrial waves) that carry the broadcast signal. The transmitted broadcast waves are relayed either directly or by terrestrial relay stations, and the broadcast signal carried by the transmitted broadcast waves is transmitted to the receiving equipment 10.

[0090] BS broadcasting is provided using a transmission line that includes a BS satellite. The broadcasting equipment 20b transmits the broadcast signal to the radio wave transmitting equipment (earth station), and the radio wave transmitting equipment transmits the broadcast waves carrying the broadcast signal to the BS satellite. The BS satellite relays the broadcast waves received from the radio wave transmitting equipment. The receiving equipment 10 receives the broadcast signal carried by the broadcast waves relayed by the BS satellite. CS broadcasting is provided using a transmission path that includes a CS satellite. The broadcasting equipment 20c transmits the broadcast signal to the radio wave transmitting equipment (earth station), and the radio wave transmitting equipment transmits the broadcast waves carrying the broadcast signal to the CS satellite. The CS satellite relays the broadcast waves received from the radio wave transmitting equipment. The receiving equipment 10 receives the broadcast signal carried by the broadcast waves relayed by the CS satellite.

[0091] Terrestrial digital broadcasting, BS broadcasting, and CS broadcasting are provided using channels belonging to different channel bands. Therefore, the receiving processing unit 110 of the receiving device 10 can receive and receive broadcast content and control information from terrestrial digital broadcasting, BS broadcasting, and CS broadcasting by selecting a channel. As described above, the CAS program is transmitted as part of the common data for all receivers. This is because the common data for all receivers is intended to be provided to all receiving devices, regardless of the manufacturer or model of the receiving device. However, notification information regarding the transmission of the common data for all receivers is set separately for terrestrial digital broadcasting, BS broadcasting, and CS broadcasting. Broadcasting devices 20a, 20b, and 20c each transmit the common data for all receivers at regular intervals. The common data for all receivers is specified, for example, in the standard ARIB STD-B21, to be transmitted at least once every 20 minutes.

[0092] As described above, the transmission of the CAS program is notified using the value of the table identification extension (table_id_ext) described in the SDTT which indicates the notification information. However, different values ​​may be set depending on the broadcasting method. In the example in Figure 13, the table identification extension (table_id_ext) is set to "0xFFFA", "0xFFF8", "0xFFFE", or "0xFFFC" for terrestrial digital broadcasting, BS broadcasting, and CS broadcasting, respectively. In Figure 13, "Common data for terrestrial digital television broadcasting" corresponds to the common data for all receivers in terrestrial digital broadcasting. "BS common data" corresponds to the common data for all receivers in BS broadcasting. "Broadband CS common data" corresponds to the common data for all receivers in CS broadcasting.

[0093] Broadcasting devices 20a, 20b, and 20c, which transmit broadcast signals on channels notified by SDTT, each transmit the CAS program during the transmission period notified by SDTT. As described above, DII and DDB are used in the transmission of the CAS program. DII contains information about the CAS program provided as downloadable data. DDB stores the CAS program.

[0094] In the example in Figure 14, the CAS program information is transmitted in the DII by describing "9" as the module identifier (module_id) value and "CASPRG" as the Name descriptor. This notifies information related to downloads targeting CAS programs. In the DDB associated with that DII, the CAS program data indicating the CAS program is included in the CAS program descriptor (CasProgramInformation()).

[0095] Next, we will describe examples of setting data tables and descriptors related to the transmission of CAS programs. Figure 15 shows an example of the SDTT settings according to this embodiment. In SDTT, the table identification extension (table_id_ext), module identification (module_id), name descriptor, and download identification (download_id) are related to the distribution of the CAS program. The table identification extension (table_id_ext) provided for BS broadcasting, CS broadcasting, and terrestrial digital broadcasting is specified as "0xFFFE", "0xFFFC", "0xFFFA", or "0xFFF8", respectively. The module identification (module_id) is specified as "9". In the Name descriptor field, "CASPRG" is specified. The download identification (download_id) describes the download identification related to the distribution of that CAS program. The same download identification as this download identification is also described in the DII and DDB related to the distribution of that CAS program. That is, the SDTT, which includes CAS program information, notifies the receiving device 10 of the scheduled download of the CAS program. Then, using the DII and DDB which specify the same download identification as the download identification specified in SDTT, the download of the CAS program notified in SDTT is executed.

[0096] The table identifier extension (table_id_ext) is described in the SDTT body (Figure 18). The module identifier (module_id), name descriptor, and download identifier (download_id) are described in the download content descriptor (Download_content_descriptor()) (Figure 19). The module identifier (module_id) is an identifier that indicates the individual module used for file transmission in downloads. The name descriptor is originally used to describe a name that uniquely identifies the module. However, in this embodiment, the string "CASPRG", which indicates CAS program information, is described. The name descriptor is stored in the module information (module_info_byte) field of the download content descriptor (Download_content_descriptor()). The download identifier (download_id) describes the download acceptance number that identifies each download. The download content descriptor (Download_content_descriptor()) is described in the SDTT descriptor area (descriptors()) (Figure 18).

[0097] Figure 16 shows an example of the DII settings according to this embodiment. In the DII, the model field (model), module identifier (moduleId), specifierType field, Name descriptor, and download identifier (downloadID) are related to the distribution of the CAS program. In the model field (model), the same value as the value specified in the table identifier extension (table_id_ext) of the SDTT is specified. In the module identifier (moduleId), "9" is specified. In the Name descriptor, "CASPRG" is specified. In the download identifier (downloadId), the same as the download identifier (downloadId) specified in the SDTT is specified. As a result, the information of the CAS program related to the download notified by the SDTT is notified to the receiving device 10.

[0098] The module identifier (moduleId), name descriptor, and download identifier (downloadID) are described in the DII body (Figure 20). The name descriptor is stored in the module information (module_info_byte) field. The model field (model) is included in the compatibility descriptor (CompatibilityDescriptor()) (Figure 21). The compatibility descriptor (CompatibilityDescriptor()) is described in the compatibility descriptor field (compatibilityDescriptor) of the DII (Figure 20).

[0099] Figure 17 shows an example of the DDB settings according to this embodiment. In the DDB, the module identifier (moduleId) and download identifier (downloadID) are parameters related to the distribution of the CAS program. For the module identifier (moduleId), "9" is specified. For the download identifier (downloadId), the same as the download identifier (downloadId) notified by SDTT or DDI is specified. The CAS program is stored in the CAS program descriptor (CasProgramInformation()) (Figure 9). The description area (blockDataByte()) stores the CAS program descriptor (CasProgramInformation()) in which the CAS program is described. This allows the receiving device 10 to identify the DDB that stores part or all of the CAS program notified by DII.

[0100] The module identifier (moduleId) is described in the DDB body (Figure 22). The download identifier (downloadID) is described in the dsmcc download data header descriptor (dsmccDownloadDataHeader()) (Figure 23). The dsmcc download data header descriptor (dsmccDownloadDataHeader()) describes the header information of the download data (in this embodiment, the CAS program) transmitted using the DSM-CC method.

[0101] Next, an example of the download reservation process in SDTT according to this embodiment will be described. Figure 24 is a flowchart illustrating the download reservation process in SDTT according to this embodiment. The processes in steps S302-S306, S312, and S314 in Figure 24 are the same as the processes in steps S102-S106, S110, and S112 in Figure 10, respectively, so their explanations will be used accordingly.

[0102] The processing in step S308 begins if the data table stored in the TS packet in step S306 is determined to be SDTT (step S306 YES). (Step S308) The update processing unit 122u (Figure 2) of the receiving device 10 determines whether or not to distribute common data for all receivers based on whether or not the value of the table identification extension (table_id_ext) described in the SDTT input from the broadcast decoding unit 114 corresponds to a predetermined value for the broadcasting method on the selected channel. Here, the update processing unit 122u identifies the broadcasting system to which the currently selected channel belongs, based on the channel band set for BS broadcasting, CS broadcasting, and terrestrial digital broadcasting. If the identified broadcasting system is BS broadcasting, the update processing unit 122u proceeds to step S310 if the value of the table identification extension (table_id_ext) is "0xFFFE" (step S308 YES). If the identified broadcasting system is CS broadcasting, the process proceeds to step S310 if the value of the table identification extension (table_id_ext) is "0xFFFC" (step S308 YES). If the identified broadcasting system is terrestrial digital broadcasting, the process proceeds to step S310 if the value of the table identification extension (table_id_ext) is "0xFFF8" or "0xFFFA" (step S308 YES). If the value of the table identification extension (table_id_ext) is any other value (step S308 NO), the process returns to step S304.

[0103] (Step S310) The update processing unit 122u refers to the SDTT and determines whether or not the CAS program is distributed based on whether or not "CASPRG" is specified in the Name descriptor. If "CASPRG" is specified (Step S310 YES), the process proceeds to step S312. If "CASPRG" is not specified (Step S310 NO), the process returns to step S304.

[0104] Next, an example of the process for starting the download of the CAS program according to this embodiment will be described. Figure 25 is a flowchart illustrating the process for starting the download of the CAS program according to this embodiment. The processes in steps S402-S406 and S410-S416 in Figure 25 are the same as the processes in steps S202-S206 and S210-S216 in Figure 11, respectively, so their explanations will be used accordingly.

[0105] The processing in step S408 begins after the processing in step S406 is completed. (Step S408) The update processing unit 122u identifies the Name descriptor described in the module information (module_info_byte) field of the DII input from the broadcast decoding unit 114. The update processing unit 122u determines whether "CASPRG" is specified for the identified Name descriptor. If "CASPRG" is specified (Step S408 YES), the process proceeds to step S410. If "CASPRG" is not specified (Step S408 NO), the process returns to step S406.

[0106] As described above, the receiving device 10 according to this embodiment includes a receiving processing unit 110 that decrypts encrypted content from a received signal obtained by receiving a broadcast wave, a CAS processing unit 124 that acquires a decryption key for decrypting the content according to a CAS program, an output processing unit 130 that outputs the decrypted content, and a software update unit 122. The receiving processing unit 110 detects notification information (e.g., SDTT) regarding the transmission of download data from the received signal, and when the notification information contains CAS program information (e.g., "CASPRG") indicating a CAS program, the software update unit 122 acquires download instruction information (i.e., DII) and download data blocks (i.e., DDB) during the transmission period notified by the notification information, extracts a CAS program from the download data block that contains a download identification common to the download identification described in the DII download instruction information specifying the CAS program information, and sets the extracted CAS program in the CAS processing unit 124. With this configuration, the receiving device 10 can detect the distribution of a CAS program based on whether or not CAS program information is specified in the notification information, and can identify the download instruction information and download data block that are identified by the download identifier indicating the distribution. The receiving device 10 can obtain the CAS program from the download data block indicated by the download instruction information. Since the distribution of a CAS program can be immediately identified from various download data, the processing load required to wait for the distribution of a CAS program can be reduced.

[0107] Furthermore, the receiving processing unit 110 may detect a descriptor (for example, a Name descriptor) indicating CAS program information from the notification information that notifies the distribution of data common to all receivers. With this configuration, the CAS program can be immediately identified from the downloaded data, which is distributed as common data for all receivers.

[0108] Furthermore, if the notification information includes a table identifier extension (e.g., table_id_ext) indicating the distribution of common data for all receivers related to the broadcasting system (e.g., BS broadcasting, CS broadcasting, and terrestrial digital broadcasting) for the broadcasting channel of the received signal, the limited reception processing program information may be detected from the notification information. With this configuration, based on the value of the table identifier extension specified in the notification information, it is possible to determine the distribution of data common to all receivers according to the broadcasting method of the selected broadcast channel.

[0109] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configurations are not limited to the embodiments described above, and include designs and the like that do not depart from the spirit of this invention. The configurations described in the embodiments described above can be combined arbitrarily. Furthermore, parts of each configuration may be omitted or modified. [Explanation of Symbols]

[0110] S1, S2…Broadcasting system, 10…Receiving device, 20, 20a, 20b, 20c…Broadcasting equipment, 102…Operation input unit, 104…Channel selection processing unit, 110…Receiving processing unit, 112…Broadcast receiving unit, 114…Broadcast decoding unit, 122…Software update unit, 122c…Verification processing unit, 122s…Software information storage unit, 122u…Update processing unit, 124…CAS processing unit, 130…Output processing unit, 132…Video decoding unit, 134…Audio decoding unit

Claims

1. A receiving processing unit that decrypts encrypted content from a received signal obtained by receiving a broadcast wave, A limited reception processing unit that obtains a decryption key for decrypting the content according to a limited reception processing program, An output processing unit that outputs the decoded content, It includes a software update unit, The receiving processing unit detects notification information regarding the transmission of downloaded data from the received signal, When the notification information contains limited reception processing program information indicating a limited reception processing program, the software update unit, During the transmission period notified in the notification information, download instruction information and download data blocks are acquired. The limited reception processing program is extracted from the download data block containing download identification information that is common to the download identification information described in the download instruction information indicating the limited reception processing program information. The extracted limited reception processing program is set in the limited reception processing unit. Receiving device.

2. The receiving processing unit, The descriptor indicating the limited reception processing program information is detected from the notification information that notifies the distribution of data common to all receivers. The receiving device according to claim 1.

3. The receiving processing unit, When the notification information contains an extension of a table identifier indicating the distribution of common data for all receivers related to the broadcasting system for the broadcasting channel of the received signal, the limited reception processing program information is detected from the notification information. The receiving device according to claim 2.

4. Broadcasting equipment for transmitting the aforementioned broadcast waves, The receiving device is as described in claim 1. Broadcasting system.

5. Decrypt the encrypted content from the received signal obtained by receiving broadcast waves. Obtain a decryption key to decrypt the content according to the limited reception processing program, A receiving method in a receiving device that outputs the decoded content, The notification information regarding the transmission of downloaded data is detected from the received signal. When the aforementioned notification information includes information about a limited reception processing program, During the transmission period notified in the notification information, download instruction information and download data blocks are acquired. The limited reception processing program is extracted from the download data block containing download identification information that is common to the download identification information described in the download instruction information indicating the limited reception processing program information. Set the extracted limited reception processing program. Reception method.

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