JP2005236741A - Cable television receiving terminal, oob server and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein it is necessary to prepare equipment close to actual operation because of the requirement for a head end and a cable card, and it is very expensive, and a large amount of labor to construct the environment is required since the head end includes the equipment for guaranteeing connection with a plurality of terminals. <P>SOLUTION: The cable television receiving terminal is provided with an executing means for executing an application; a first receiving means for receiving data outputted from an OOB (out of band) server for outputting a second data format different from a first data format that the head end transmits via an OOB; a converting means for converting data of the second data format received by the first receiving means into the first data format; and a library for offering data converted, by the converting means to the application. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a development environment for emulation of functions provided for applications executed in digital cable television.

  An application execution and application development environment in a conventional digital cable television will be described.

  FIG. 19 is a block diagram showing the relationship of the devices constituting the cable system, and is composed of a head end 1901, three terminal devices A 1911, a terminal device B 1912, and a terminal device C 1913. The head end 1901 transmits broadcast signals including video / audio / data and applications to a plurality of terminal devices, and receives data transmission from the terminal devices.

  In order to realize this, the frequency band used for transmission between the head end 1901 and the terminal device A 1911, the terminal device B 1912, and the terminal device C 1913 is divided and used. FIG. 20 is a table showing an example of frequency band division. Frequency bands are roughly classified into two types, Out Of Band (abbreviated as OOB) and In-Band. 5 to 130 MHz is allocated to the OOB, and is mainly used for data exchange between the head end 1901 and the terminal device A 1911, the terminal device B 1912, and the terminal device C 1913. 130 MHz to 864 MHz is assigned to In-Band and is mainly used for broadcast channels including video and audio. QPSK modulation is used for OOB, and QAM64 modulation is used for In-Band. FIG. 21 is an example of a more detailed use of the OOB frequency band. 70 MHz to 74 MHz are used for data transmission from the head end 1901, and all the terminal devices A 1911, terminal devices B 1912, and terminal devices C 1913 receive the same data from the head end 1901. On the other hand, 10.0 MHz to 10.1 MHz is used for data transmission from the terminal device A 1911 to the head end 1901, and 10.1 MHz to 10.2 MHz is used for data transmission from the terminal device B 1912 to the head end 1901. 2 MHz to 10.3 MHz is used for data transmission from the terminal device C 1913 to the head end 1901. Thereby, data specific to each terminal device can be transmitted from each terminal device A 1911, terminal device B 1912, and terminal device C 1913 to the head end 1901. FIG. 22 is an example of use for the In-Band frequency band. 150-156 MHz and 156-162 MHz are assigned to TV channel 1 and TV channel 2, respectively, and thereafter, TV channels are assigned at intervals of 6 MHz. After 310 MHz, radio channels are allocated in 1 MHz units. Each of these channels may be used as an analog broadcast or a digital broadcast. In the case of digital broadcasting, it is transmitted in a transport packet format based on the MPEG2 specification, and applications can be transmitted in addition to audio and video.

  The terminal device A 1911, the terminal device B 1912, and the terminal device C 1913 receive the OOB and the in-band broadcast signal from the head end 1901, reproduce the video / audio, and download and execute the application.

  FIG. 23 is a block diagram illustrating a hardware configuration of the terminal device. 2300 is a terminal device, QAM demodulator 2301, QPSK demodulator 2302, QPSK modulator 2303, TS decoder 2305, audio decoder 2306, speaker 2307, video decoder 2308, display 2309, secondary storage 2310, primary storage 2311, an input unit 2313, and a CPU 2314. In addition, a cable card (R) 2304 can be attached to and detached from the terminal device 2300.

  FIG. 24 is a flat-screen television that is an example of the appearance of the terminal device 2300.

  Reference numeral 2401 denotes a case of a flat-screen television, which incorporates all the components of the terminal device 2300 except the CableCard® 2304.

  Reference numeral 2402 denotes a display, which corresponds to the display 2309 in FIG.

  Reference numeral 2404 denotes a signal input terminal for connecting a cable line to transmit / receive a signal to / from the head end 1901. The signal input terminal is connected to the QAM demodulator 2301, the QPSK demodulator 2302, and the QPSK modulator 2303 in FIG.

  Reference numeral 2405 denotes a CableCard (R) corresponding to the CableCard (R) 2304 in FIG. The CableCard (R) 2304 has a form independent of the terminal device 2300 and can be attached to and detached from the terminal device 2300 as the CableCard (R) 2405 in FIG. Details of the CableCard (R) 2304 will be described later.

  Reference numeral 2406 denotes an insertion slot for inserting CableCard (R) 2405.

  With reference to FIG. 23, a mechanism in which the terminal 2300 reproduces video / audio will be described. The QAM demodulator 2301 demodulates a signal transmitted from the head end 1901 by QAM modulation using In-band according to an instruction from the CPU 2314, and delivers the signal to the CableCard (R) 2304. Here, the demodulated signal is a scrambled MPEG2 transport stream.

  The CableCard (R) 2304 descrambles the received signal and delivers it to the TS decoder 2305. The connection interface of the CableCard (R) 2304 is defined by the OpenCable (R) CableCard Interface Specification (OC-SP-CC-IF-I15-031121) and the specification referred to from this specification.

  Based on the instruction to the CPU 2314, the TS decoder 2305 extracts an audio packet from the MPEG2 transport stream descrambled by the CableCard®, and delivers it to the audio decoder 2306. The audio decoder 2306 converts the received audio packet from digital to analog and reproduces it using the speaker 2307. At the same time, the TS decoder 2305 extracts a video packet and delivers it to the video decoder 2308. The video decoder 2308 converts the received video packet from digital to analog and reproduces it using the display 2309.

  With reference to FIG. 23, a mechanism in which the terminal 2300 communicates with the head end 1901 and acquires channel information from the head end 1901 will be described.

  Upon receiving an instruction from the CPU 2314, the QPSK demodulator 2302 demodulates a signal that has been QPSK-modulated and transmitted from the head end 1901 using OOB, and delivers the signal to the CableCard (R) 2304.

  The CableCard (R) 2304 converts the received signal into data of an appropriate format in accordance with the OpenCable (R) CableCard Interface Specification (OC-SP-CC-IF-I15-031121), and passes it to the CPU 2314. Here, two types of appropriate data are defined: MPEG section data and IP data. The MPEG section data is mainly used for one-way communication that is used for the head end 1901 to notify the terminal 2300 of channel information (such as the relationship between frequency and channel name) transmitted in-band. The IP data is used for two-way communication between the head end 1901 and the terminal 2300. The IP data obtained through the QPSK demodulator 2302 is data from the head end 1901 toward the terminal 2300. On the other hand, when performing IP data from the terminal 2300 to the head end 1901, the CPU 2314 delivers the IP data to be transmitted to the CableCard (R) 2304. The CableCard (R) 2304 converts the received IP data into appropriate data by, for example, scrambling, and passes the data to the QPSK modulation unit 2303. The QPSK modulation unit 2303 modulates the received data and delivers it to the head end 1901.

  Here, between the CableCard (R) and the head end 1901, an original communication method or a scramble / descramble method can be used, and the head end manufacturer provides both. As described above, the standard specifications of the interface between the terminal 2300 and the CableCard (R) have been established. By using the CableCard (R), the terminal 2300 employs a plurality of types of headends 1901 adopting different transmission methods. Can be connected with.

  The CPU 2314 controls video / audio reproduction and communication with the head end 1901 described above. This control is realized by the CPU 2314 operating the built-in programs and applications stored in the secondary storage unit 2310 and the primary storage unit 2311. FIG. 25 is a block diagram showing the configuration of the built-in program and application. The OS 2501 is a built-in program that is first activated by the CPU 2314 and is stored in the secondary storage unit 2310. An OS 2501 is basic software that controls execution of a built-in program and an application that the CPU 2314 operates. The zapper 2502 is a built-in program that is activated by the OS 2501 and receives a user input from the input unit 2313 to change a channel. Java (R) 2503 is middleware that operates the downloaded application 2504 and is activated by the OS 2501. Specifically, a function defined by OpenCable (R) Application Platform Specification (OC-SP-OCAP1.0-IF-I09-031121) is realized. These functions can be performed by the application 2504. The functions include a function of drawing graphics on the display 2309, a function of receiving channel information received from the head end 1901 by the terminal 2300, and a function of performing bidirectional communication with the head end 1901.

  The application 2504 is downloaded by Java (R) 2503 and stored in the primary storage unit 2311. Downloading is realized by extracting from the signal transmitted from the head end 1901 using In-band. For detailed specifications, see OpenCable (R) Application Platform Specification (OC-SP-OCAP1.0-IF- I09-031121).

  In order to develop the application 2504 in the digital cable system described above, it is necessary to prepare all the cable television system apparatuses shown in FIG. 19 and confirm the operation in the system. In particular, when an application acquires channel information from the head end 1901 or performs bidirectional communication with the head end 1901, these data are transmitted through the Cable Card (R) 2304. Therefore, the head end 1901 and the Cable Card (R) 2304 are used. It is essential.

  On the other hand, Japanese Patent Laid-Open No. 2003-69524 discloses a technique for constructing a test execution environment that is inexpensive and close to actual operation by artificially generating a multi-channel terrestrial digital broadcast wave. In general, multi-channel terrestrial digital has three methods for artificially generating broadcast waves. (1) Prepare multiple terrestrial digital broadcast modulators. (2) The output of one terrestrial digital broadcast modulator is converted into the frequency of the set channel by a plurality of frequency converters and output. (3) The Tokyo Pilot Experiment Council actually receives the terrestrial digital broadcast that is being emitted, converts it to a plurality of frequencies with a plurality of frequency converters, and outputs it.

  Method (1) is the most ideal, but it is very expensive because a plurality of actual broadcast modulators are used. In the method (2), the output of one terrestrial digital broadcast modulator is frequency-converted by a plurality of frequency converters, so that the output signal becomes a synchronized signal of the same spectrum, which is different from the actual radio wave emission situation. This makes it impossible to conduct tests that match the actual situation. Since the method (3) receives radio waves emitted in the air, there is a problem that the stability and the C / N ratio (Carrier to Noise ratio) differ depending on the location. Japanese Patent Laid-Open No. 2003-69524 generates a plurality of OFDM signal generators that generate OFDM signals conforming to the specifications of digital broadcasting, convert the signals to IF frequency signals, and output the signals from the OFDM signal generators. A plurality of RF converters that respectively convert IF frequency signals to set channel frequencies and output, and an RF mixer that mixes multi-channel OFDM signals output from the RF converter and outputs them from one output terminal It is solved by having.

  Japanese Patent Laid-Open No. 7-200434 discloses a technique for operating an application constructed on different communication protocols such as TCP / IP and OSI on the OSI protocol. By preparing a library that realizes TCP / IP in a pseudo manner on the OSI protocol, a TCP / IP environment can be realized in a pseudo manner on an OSI protocol environment and an application using TCP / IP can be operated. . The outline of this patent will be described with reference to FIG. FIG. 26A shows an example of an application using a conventional TCP / IP library. In FIG. 26A, reference numeral 2601 denotes an application using a TCP / IP library, 2602 denotes a socket, and 2603 denotes a TCP / IP library. Communication using TCP / IP is realized using a socket. Therefore, the application 2601 uses the socket 2602. The socket 2602 performs network communication using the TCP / IP library 2603. (2) is an overview of this patent. Reference numeral 2604 denotes an OSI library. Others are the same as those described in (1) and are omitted. In this patent, a portion that conventionally used a TCP / IP library in a socket is realized by converting the mapping so as to use the OSI library. As a result, the application can perform network communication without being aware of the OSI library and without rewriting for the OSI library.

With this technology, an application using a protocol that is not originally supported by the execution environment can be executed.
JP 2003-69524 A Japanese Patent Laid-Open No. 7-200344

  However, in the conventional technology, when developing an application that operates in a digital cable system, a head end and a cable card are required, and thus it is necessary to prepare equipment close to actual operation. The head end includes devices for assuring connection with a plurality of terminals, and is very expensive. In addition, a great amount of labor is required to construct this environment. It is necessary to attempt to reproduce the actual system environment in a pseudo manner as disclosed in JP-A-2003-69524.

  An object of the present invention is to provide a simulated head end and an ADK card that can realize the simulated environment of the head end and the CableCard® at low cost and with little effort. By using this environment, an application developer can build an application development environment and develop an application at low cost and with little effort.

  In order to solve the conventional problem, in a cable television receiving terminal capable of transmitting and receiving data from a head end in a cable television system via an OOB, execution means for executing an application, and the head end transmitting via the OOB First receiving means for receiving data output from an OOB server that outputs a second data format different from the first data format, and data in the second data format received by the first receiving means, Conversion means for converting the data into one data format, and a library for providing the data converted by the conversion means to the application.

  According to the present invention, in a cable television receiving terminal capable of transmitting and receiving data from the head end in the cable television system via the OOB, the execution means for executing the application and the first data format transmitted by the head end via the OOB First receiving means for receiving data output from an OOB server that outputs a second data format different from the first data format, and data in the second data format received by the first receiving means as the first data format. The cable television receiving terminal has been sent in a pseudo manner from an OOB server that emulates a head end by providing a conversion means for converting the data into the application and a library for providing the data converted by the conversion means to the application. Receive and convert data to run on cable TV receivers To the application, it is possible to provide the same data as the data sent from the headend.

  The cable television receiving terminal further connects a second receiving means for receiving data transmitted by the head end via the OOB, and switches the first receiving means and the second receiving means to connect to the library. By providing the switching means, the cable television receiving terminal can be connected to both the OOB server and the head end in actual broadcasting.

  Further, the cable television receiving terminal further includes a shape in which the first receiving unit is separable from the cable television receiving terminal, and the cable television receiving terminal includes a connection unit that connects the first receiving unit. Thus, when a cable television receiving terminal has a slot for inserting a CableCard (R) or a similar slot, the first receiving means is inserted into that slot, so that the OOB server emulating the headend can be simulated. By receiving and converting the data sent automatically, it is possible to provide data similar to the data sent from the headend to an application operating on the cable television receiving terminal. This realizes easy expansion of the functions of mass-produced cable television receiving terminals.

  In the cable television receiving terminal, the first data format is MPEG section data, the second data format is IP data, the converting means receives the IP data, and By converting the IP data into the MPEG section data, the MPEG section data originally transmitted by the head end can be received by a simple method.

  In the cable television receiving terminal, the first data format is MPEG section data or first IP data, the second data format is second IP data, and the second data format The IP data includes a data format identifier for identifying the format of the data before conversion, and the conversion means receives the second IP data, and based on the data format identifier, the second IP data The MPEG section data and the IP data originally transmitted by the head end can be received by a simple method by converting the MPEG section data into the MPEG section data or the first IP data.

  In addition, the cable television receiving terminal can be connected to a specific OOB server by further including an initialization unit that establishes a connection with the OOB server. This enables data transmission / reception with a desired OOB server in an environment where a plurality of OOB servers and cable television receiving terminals are connected to the network.

  The cable television receiving terminal further includes transmission data generating means for generating data in the second format based on the second data format, and data in the second data format generated by the transmission data generating means. Is provided to the OOB server, the IP data that should be sent to the headend can be transmitted to the OOB server.

  Furthermore, a second data format that can be converted into a first data format that the head end transmits via the OOB to a cable television receiving terminal that can send and receive data via the OOB from the head end in the cable television system. By providing a data generation means to be generated and a transmission means for transmitting the data generated by the data generation means to the cable television receiving terminal, it is possible to make it simpler and easier in a simple manner without using a headend in an actual broadcasting environment. Data to be transmitted by a simple head end can be transmitted to the cable television receiving terminal. Specifically, in the actual broadcasting environment, a modulator is required, but by replacing the TCP / IP network, the modulator and the accompanying equipment are not required, so the actual broadcasting environment can be easily and inexpensively made. Can be emulated.

  Further, the OOB server can be connected to a specific cable television receiving terminal by further comprising an initialization means for establishing a connection with the cable television receiving terminal. This enables data transmission to a desired cable television receiving terminal in an environment where a plurality of OOB servers and cable television receiving terminals are connected to the network.

  Further, the OOB server further includes conversion means for converting the first data format into the second data format, so that the data to be given to the head end in an actual broadcasting environment can be simulated in a simpler and simpler manner. It is possible to transmit to the cable TV receiving terminal by the facility.

  The OOB server may further include the first data format is MPEG section data, the second data format is IP data, and the conversion means receives the MPEG section data, and the MPEG section data. By converting the IP data into the IP data, the MPEG section data given to the head end in the actual broadcast environment can be transmitted as it is to the cable television receiving terminal with simpler equipment.

  In the OOB server, the first data format is first IP data, the second data format is second IP data, and the conversion means includes the first IP data. By converting the first IP data to the second IP data, the IP data to be given to the head end in an actual broadcasting environment is directly transmitted to the cable television receiving terminal with a simpler facility. Make it possible.

  The OOB server further includes a receiving unit that receives the data in the second data format, and an inverse conversion unit that converts the data received by the receiving unit into the first data format. Data transmitted from the television receiving terminal can be received.

  Further, in a cable television receiving terminal, which is a computer-readable recording medium and can transmit and receive data via the OOB from the head end in the cable television system, the execution means for executing the application, and the head end transmits via the OOB First receiving means for receiving data output from an OOB server that outputs a second data format different from the first data format, and data in the second data format received by the first receiving means, Portability by using a computer-readable recording medium in which a conversion unit for converting to the first data format and a program that performs each function of a library that provides the application with the data converted by the conversion unit is recorded Can be increased.

  A first data format that is a computer-readable recording medium that is transmitted from the head end via the OOB to a cable television receiving terminal that can transmit and receive data from the head end in the cable television system via the OOB. A computer-readable recording medium storing a program that performs each function of a data generation unit that generates a second data format that can be converted into data and a transmission unit that transmits data generated by the data generation unit to the cable television receiving terminal By using a recording medium, portability can be improved.

(Embodiment 1)
An application development environment according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an apparatus constituting an application development environment. Referring to FIG. 1, the application development environment includes an STB (terminal device) 101, a television 102, an ADK card 103, an OOB server 104, a serial terminal 105, and an MPEG server 106.

  STB is an abbreviation for Set Top Box, which is a television receiver tuner. Since the internal hardware configuration of the STB itself is a well-known technique, the details are omitted, and only the portion related to the present invention is outlined. This STB is an STB conforming to the US digital cable TV standard OpenCable (R) Application Platform Specification (OC-SP-OCAP1.0-IF-I09-031121). The feature of this standard is that the STB has a CableCard (R) insertion slot indicated by 101a in the figure. CableCard (R) is a card that conforms to the PCMCIA interface, and is a known technique having a function of descrambling the scrambled video received by the STB. The interface between the CableCard (R) and the STB main body is defined in the OpenCable (R) CableCard Interface Specification (OC-SP-CC-IF-I15-031121) and the specifications referenced from this specification. Details regarding software operating on the STB 101 will be described later.

  The television 102 is specifically composed of a cathode ray tube or liquid crystal, and displays the video transmitted from the STB 101.

  The ADK card 103 is a card for expanding the functions of the Ether port 103a, the serial port 103b, and the LVDS port 103c to the STB 101. Here, LVDS is an abbreviation for Low Voltage Differential Signaling, and is a known method for transferring data at high speed and low power consumption (one to one). ADK is an abbreviation for Application Development Kit. In the application development environment, the ADK card 103 having the same interface is inserted into the CableCard (R) insertion slot 101a instead of the CableCard (R), and the STB function is expanded. FIG. 2 is an example of the appearance of the ADK card. Reference numeral 200 denotes an ADK card, 201 is an LVDS port, 202 is a serial port, 203 is an Ether port, and 204 is a PCMCIA interface connector to be inserted into a CableCard (R) insertion slot.

  The Ether port 103a, serial port 103b, and LVDS port 103c on the ADK card 103 are composed of a plurality of pins, and a signal determined by the specification flows through each pin. The signal received by each pin flows to the corresponding PCMCIA card interface pin and transmits the signal to the STB 101. Conversely, when the STB 101 transmits signals to the outside using the Ether port 103a and the serial port 103b on the ADK card 103, the STB 101 has a PCMCIA card interface corresponding to each pin of the Ether port 103a and the serial port 103b. The necessary signal is sent to the pins. Here, the correspondence between the pins of the Ether port 103a, the serial port 103b, and the LVDS port 103c and the pins of the PCMCIA card interface is implementation-dependent, and any combination is possible. However, if the pins are mapped so that the signals of the three ports do not mix, or if the same pin is shared, it is implemented so that the signals are not mixed, such as by performing exclusive control by time. The

  The OOB server 104 is a server for emulating OOB communication of a head end (station side system) in a digital cable TV system, and is configured by a personal computer or the like having a network interface that supports a TCP / IP communication function. Is done. Details of the software operating on the OOB server 104 will be described later.

  The serial terminal 105 is configured by a personal computer or the like provided with a serial input / output interface (RS-232C format). The serial terminal 105 receives the debug character string information output by the application running on the STB 101 through the serial input / output interface, and displays it on a display or the like provided in the serial terminal 105. By using the serial terminal 105, it is possible to debug an application operating on the STB 101.

  The MPEG server 106 emulates in-band transmission at the head end in a digital cable TV system. Specifically, the given MPEG2 transport stream is transmitted according to the LVDS format. The STB 101 can normally receive a signal equivalent to the signal demodulated by the tuner by receiving the signal output from the MPEG server 106 through the ADK card 103.

  Next, software that operates on the STB 101 and the OOB server 104 that is the center of the present invention will be described.

  FIG. 3 is a block diagram showing the configuration of software that operates on the STB 101. With reference to FIG. 3, the software includes an OS 301, a zapper 302, a Java (R) 303, and an application 304.

  The OS 301 is a built-in program that is activated first when the STB 101 is activated, and is basic software that controls the execution of other built-in programs and applications. Linux or the like is an example of an OS. The OS 301 includes a kernel 301a that controls the execution of other programs and applications, and a library 301b that provides various functions to the built-in programs and applications.

  The zapper 302 is a built-in program that is activated by the OS 301 and performs channel change or the like according to a user instruction, and is a known technique.

  Java (R) 303 is middleware for operating the application 304, and is a well-known technique activated by the OS 301. Specifically, a function defined by OpenCable (R) Application Platform Specification (OC-SP-OCAP1.0-IF-I09-031121) is realized. These functions can be used by the application 304. The functions include a function of drawing graphics, a function of receiving channel information received by the STB 101 from the head end, and a function of performing bidirectional communication with the head end. In the application development environment in this embodiment, the application 304 receives channel information from the OOB server 104 through the ADK card 103 instead of the head end, and performs bidirectional communication with the OOB server 104.

  The application 304 is downloaded by Java (R) 303 and stored in the STB 101. The download is realized by extracting from the signal transmitted from the head end, and the detailed specification is defined in OpenCable (R) Application Platform Specification (OC-SP-OCAP1.0-IF-I09-031121). ing. In the application development environment in the present embodiment, the STB 101 downloads the application 304 from the MPEG2 transport stream sent from the MPEG server 106 instead of the head end.

  In the software configuration in the present embodiment, the zapper 302 and Java (R) 303 are exactly the same as those used in the actual broadcast environment, and no changes are made to configure the application development environment. On the other hand, the library 301b of the OS 301 is changed from the state of the actual broadcast environment in order to configure the application development environment.

  FIG. 4 is a schematic diagram showing the relationship between the program components added to configure the application development environment in the library 301b and the related program components.

  A card library 401 is a library for controlling the CableCard (R) and exchanging data when the CableCard (R) is inserted into the CableCard (R) insertion slot in the actual broadcasting environment. The main function of the card library 401 is to send and receive data to and from the headend through a CableCard in an actual broadcast environment. The operation of the card library 401 realizes the operation on the terminal side defined in the OpenCable (R) CableCard Interface Specification (OC-SP-CC-IF-I15-031121) and the specification referenced from this specification. doing.

  Reference numeral 402 denotes an emulation library, which is used to exchange data from the OOB server sent through the ADK card 103 when the ADK card 103 is inserted into the CableCard (R) insertion slot in the application development environment. It is. FIG. 5 shows the configuration of the emulation library. Referring to FIG. 5, 501 is an IP data receiving unit, 502 is a section data receiving unit, 503 is an IP data transmitting unit, 504 is a packet decoder, 505 is a packet encoder, 506 is a TCP / IP library, and 507 is initialized. Represents a part.

  The IP data receiving unit 501 is an interface that receives an IP packet from the packet decoder 504 and delivers the IP data to upper layer software. Here, the upper software is a socket interface 405 with reference to FIG.

  The section data receiving unit 502 is an interface that receives MPEG section data from the packet decoder 504 and delivers the MPEG section data to upper layer software. Here, the upper software is the OOB SI library 404 with reference to FIG.

  The packet decoder 504 extracts IP data or MPEG section data from the payload of the IP packet received from the TCP / IP library 506 and passes it to the IP data receiving unit 501 or the section data receiving unit 502. FIG. 6 shows the format of IP packet data transmitted and received by the emulation library 402. FIG. 6A shows the relationship between the IP packet and the OOB packet. The IP packet 610 has a known format composed of a header 611 and a payload 612. Therefore, description of the details of the header 611 is omitted. The OOB packet 620 is data embedded in the payload of the IP packet 610 and includes a packet header 621 and a payload 622. FIG. 6B is a table showing a configuration example of the packet header 621. Column 631 describes the component name, column 632 describes the length of data for storing the component, and column 633 describes the meaning of the component. A row 641 is a component of the component name “flag”, and 1 bit is assigned thereto. The flag expresses the type of data included in the payload 622. Specifically, a value of “0” indicates that IP data is stored in the payload, and a value of “1” indicates that MPEG section data is stored in the payload. The row 642 stores the length of data stored in the payload, which is a component of the component name “length” and has 15 bits allocated thereto. The packet header 621 may have other configurations, but at least a flag for identifying whether the data stored in the OOB packet 620 is IP data or MPEG section data is necessary.

  The operation of the packet decoder 504 will be described with reference to FIG. FIG. 7 is a flowchart showing the operation of the packet decoder 504. First, an IP packet is received from the TCP / IP library 506 (step S701). The OOB data 620 is extracted from the payload 612 of the received IP packet 610 (step S702). The payload information identifier flag included in the packet header 621 of the OOB data 620 is referred to (step S703), and when it is IP data, the information of the payload 622 is delivered to the IP data receiving unit 501 (step S704). In the case of MPEG section data, the information of the payload 622 is handed over to the section data receiving unit 502 (step S705).

  The packet encoder 505 creates an IP packet using the IP data received from the IP data transmission unit 503, and transmits the IP data to the OOB server 104 by passing it to the TCP / IP library 506.

  The format of the IP packet generated by the packet encoder 505 is the same as the format of the IP packet handled by the packet decoder 504, and an example thereof is as described with reference to FIG. With reference to FIG. 6, the operation of generating a packet encoder IP packet will be described. FIG. 8 is a flowchart showing an operation in which the packet encoder 505 generates an IP packet. Referring to FIG. 8, packet encoder 505 receives IP data from IP data transmission unit 503 (step S801). The received IP data is embedded in the payload 622 (step S802), a packet header 621 indicating that the data type of the payload 622 is IP data is created, and an OOB packet 620 is created (step S803). Next, the OOB packet 620 is stored in the payload 610 (step 804), and a necessary packet header 611 is generated to create IP packet data 610 (step S805). Finally, the created IP packet 610 is delivered to the TCP / IP library 506 and IP data is transmitted (step S806).

  The TCP / IP library 506 delivers the IP packet sent from the OOB server 104 to the packet decoder 504 and sends the IP data delivered from the packet encoder 505 to the OOB server 104. Further, the initialization unit 507 establishes a communication path with the OOB server 104. The TCP / IP library 506 performs IP data using TCP / IP. Since TCP / IP is a well-known technique for transmitting and receiving IP data, description regarding transmission and reception of IP data is omitted here.

  The initialization unit 507 establishes a communication path with the OOB server 104 using the TCP / IP library 506. The initialization unit 507 knows the IP address and port number of the OOB server, and gives these information to the TCP / IP library 506 to perform initialization processing of transmission / reception of IP data with the OOB server.

  Reference numeral 403 denotes a switcher that switches between the card library 401 and the emulation library 402. For example, in an actual broadcast environment in which CableCard (R) is inserted in the STB 101, the switcher 403 connects the socket interface 405 and the OOB SI library 404 to the card library 401. As a result, data exchange between the STB 101 and the head end is realized. In an application development environment in which an ADK card is inserted into the STB 101, the switcher 403 connects the socket interface 405 and the OOB SI library 404 to the emulation library 402. As a result, data exchange between the STB 101 and the OOB server 104 is realized.

  Reference numeral 405 denotes a socket interface, which is an interface for performing TCP / IP communication with the head end via the card library 401 or with the OOB server 104 via the emulation library 402. Referring to FIG. 3, socket interface 405 provides a TCP / IP communication function to Java® 303.

  Reference numeral 404 denotes an OOB SI library that receives MPEG section data transmitted from the head end via the card library 401 or transmitted from the OOB server via the emulation library 402. Channel information called OOB SI is assembled from the received MPEG section data. Here, the channel information is information such as a channel number, a channel name, and a frequency of each channel, and is information necessary for the STB to select a channel. Referring to FIG. 3, OOB SI library 404 provides OOB SI information to Java (R) 303. The present invention can be implemented in any form of API, data format, and the like that provide OOB SI information.

  Next, software that operates on the OOB server 104 will be described. FIG. 9 is a schematic diagram showing the configuration of OOB server software that runs on the OOB server 104. In FIG. 9, software operating on the OOB server 104 includes an OS 910, an OOB server library 920, and a server application 930.

  The OS 910 is an operating system that runs on the OOB server, and is basic software that runs applications and built-in programs on the OOB server. Examples are Linux and MicroSoft Windows (R). The OS 910 includes a TCP / IP library 911 inside. The TCP / IP library 911 provides a TCP / IP communication function to a built-in program or application operating on the OS 910.

  The OOB server library 920 includes an IP data reception unit 921, an IP data transmission unit 922, an OOB SI transmission unit 923, a packet decoder 924, a packet encoder 925, and an initialization unit 926. The transmission of MPEG section data to the STB 101 and the STB 101 IP data transmission / reception function is realized.

  The IP data receiving unit 921 is an interface for receiving IP data received by the TCP / IP library 911 via the packet decoder 924 and notifying the server application 930.

  The IP data transmission unit 922 is an interface that provides a function for the server application 930 to transmit IP data to the STB 101. The IP data received from the server application 930 is sent to the TCP / IP library 911 via the packet encoder 925.

  The OOB SI transmission unit 923 transmits MPEG section data to the STB 101 via the packet encoder 925 and the TCP / IP library 911 according to an instruction from the server application 930. Specifically, the OOB SI transmission unit 923 receives the MPEG section data itself from the server application 930 and delivers the data to the packet encoder 925. Alternatively, XML format text data representing OOB SI data may be received, the content thereof analyzed and converted into MPEG section data, and delivered to the packet encoder 925.

  The packet decoder 924 receives the IP packet from the TCP / IP library 911, extracts the IP data embedded in the payload, and delivers it to the IP data receiving unit 921. Here, the format of the IP packet handled by the packet decoder 924 is shown in FIG. FIG. 10 is a flowchart showing the operation of the packet decoder 924. 6 and 10, the packet decoder 924 receives an IP packet from the TCP / IP library 911 (step S1001). The OOB packet 620 is extracted from the payload 612 (step S1002). It is confirmed that the data type of the packet header 621 is IP data (step S1003). If the data type is IP data, the IP data stored in the payload 622 of the OOB packet 620 is extracted (step S1004) and delivered to the IP data receiving unit 921 (step S1005).

  The packet encoder 925 generates an IP packet from the data received from the IP data transmission unit 922 and the OOB SI transmission unit 923, and transmits the IP packet to the STB 101 using the TCP / IP library 911. Like the packet decoder 924, the format of the IP packet generated by the packet encoder 925 is as shown in FIG.

  FIG. 11 is a flowchart showing an operation when the packet encoder 925 receives IP data from the IP data transmission unit 922. With reference to FIGS. 6 and 11, the packet encoder 925 receives IP data from the IP data transmission unit 922 (step S1101). Next, the received IP data is stored in the payload 622 (step S1102). A packet header 621 indicating that the data type is IP data is generated, and an OOB packet 620 is generated (step S1103). The OOB packet 620 is stored in the payload 612 (step S1104). Next, a packet header 611 necessary for transmission to the STB 101 is generated, and an IP packet 610 is generated (step S1105). Finally, the IP data generated using the TCP / IP library 911 is transmitted to the STB 101 (step S1106).

  FIG. 12 is a flowchart showing an operation when the packet encoder 925 receives MPEG section data from the OOB SI transmission unit 923. The steps having the same numbers as those in FIG. 11 are the same as those in FIG. When the packet encoder 925 receives MPEG section data from the OOB SI transmission unit 923 (step S1201), the packet encoder 925 stores the received MPEG section data in the payload 622 (step S1202). A packet header 621 indicating that the data type is MPEG section data is generated, and an OOB packet 620 is generated (step S1203).

  The initialization unit 926 uses the TCP / IP library 911 to establish a communication path with the emulation library 402 in the STB 101. The initialization unit 926 knows the IP address and port number of the STB 101, gives these information to the TCP / IP library 911, and performs initialization processing of transmission / reception of IP data with the emulation library 402 in the STB 101.

  The server application 930 plays the role of a head end in an actual broadcast environment, and issues channel information transmission instructions, data transmission / reception instructions to the emulation library 402 in the STB 101. Also, OOB data to be transmitted to the emulation library 402 is held.

  FIGS. 13, 14, and 15 are flowcharts showing an example in which the emulation library 402 of the STB 101 and the OOB server library 920 of the OOB server 104 operate in cooperation. Since the two libraries operate on different apparatuses, it is possible to perform different operations at the same time.

  First, the STB 101 is activated and the emulation library 402 is activated (step S1301). Similarly, the OOB server 104 is activated and the OOB server library 920 is activated (step S1302). When the two devices are activated, the initialization unit 507 and the initialization unit 927 of each library perform initialization for establishing communication paths between the two devices (step S1303).

  Here, when the OOB server library 920 receives MPEG section data from the server application 930 (step S1304), IP data is generated by the operation shown in FIG. 12 and transmitted to the STB 101 (step S1305). Upon receiving this IP data (step S1306), the emulation library 402 extracts MPEG section data from the IP data by the operation shown in FIG. 7 (step S1307).

  When the OOB server library 920 receives IP data from the server application 930 (step S1401), IP data is generated by the operation shown in FIG. 11 and transmitted to the STB 101 (step S1402). Upon receiving this IP data (step S1403), the emulation library 402 extracts the IP data by the operation shown in FIG. 7 (step S1404).

  When the emulation library 402 receives the IP data (step S1501), the IP data is generated and transmitted to the OOB server 104 by the operation shown in FIG. 8 (step S1502). When the OOB server library 920 receives this IP data (step S1503), the OOB server library 920 extracts the IP data by the operation shown in FIG. 10 (step S1504) and delivers it to the server application 930.

  Note that the present invention can be implemented without the switcher 403 of FIG. In this case, at the time of compiling and linking software, it is possible to directly link any one of the required card library 401 or emulation library 402 so that only the linked library can operate.

(Embodiment 2)
In the first embodiment, the IP data exchanged between the STB 101 and the OOB server 104 is further stored in the IP data payload. In the second embodiment, IP data is transmitted as it is by securing two communication paths between the STB 101 and the OOB server 104.

  Only the parts different from the first embodiment will be described below.

  FIG. 16 is a block diagram showing the configuration of the emulation library 402 of the STB 101 in the second embodiment. In the figure, the components having the same numbers as those in FIG. 5 of the first embodiment are the same as the components in FIG.

  The TCP / IP library 1601 delivers only the IP data transmitted through the communication path established by the initialization unit 507 to the packet decoder 1602. Furthermore, securing of a communication path with the OOB server 104 is accepted from other than the initialization unit 507. For each established communication path, the received IP data is distributed to software that has requested establishment of the communication path. When the application 304 on the STB 101 performs TCP / IP communication with the OOB server 104, it directly requests the TCP / IP library 1601 to establish a communication path through the Java (R) 303.

  The packet decoder 1602 extracts MPEG section data from the payload of the IP packet received from the TCP / IP library 1601 and delivers it to the section data receiving unit 502. Here, the format of the IP data to be handled is the format shown in FIG. FIG. 17 is a flowchart showing the operation of the packet decoder 1602. In the figure, steps having the same numbers as those in FIG. 7 are the same as the operations in FIG. The difference is step S703 in FIG. 7 and step S1701 in FIG. Referring to FIG. 17, packet decoder 1602 refers to the data type of the packet header, and terminates the processing if it is not MPEG section data.

  FIG. 18 is a block diagram illustrating a configuration of software that operates on the OOB server 104 according to the second embodiment. In the figure, components having the same numbers as those in FIG. 9 of the first embodiment are the same as those in FIG.

  The TCP / IP library 1801 accepts securing of a communication path with the STB 101 from other than the initialization unit 926. The TCP / IP library 1801 distributes the received IP data to software that has requested establishment of a communication path for each established communication path.

  The difference between the server application 1802 and the server application 930 is that when performing TCP / IP communication with the STB 101, the server application 1802 directly requests the TCP / IP library 1801 to establish a communication path.

  Note that the second embodiment can be implemented without including the type of payload in the format of IP data to be handled. This is because the data stored in the payload is only MPEG section data. In this case, in FIG. 16 representing the operation flowchart of the packet decoder 1602, the process of step S1701 is omitted. Also, in FIG. 12 showing the operation flowchart of the packet encoder 925, the process of step S1203 generates a packet header combined with the changed packet header format.

  Through the first and second embodiments, it has been described that the Ether port 103a, the serial port 103b, and the LVDS port 103c are mounted on the ADK card 103. However, the present invention can be implemented even when the STB 101 is mounted. In this case, the TCP / IP library on the STB 101 controls the Ether port on the STB 101.

  Further, through the first and second embodiments, the OOB server 104 and the serial terminal 105 can be implemented even if they are realized by a single personal computer. Furthermore, the function of the MPEG server 106 may be provided.

  Further, through the first and second embodiments, the present invention is that the application on the STB 101 is executed by the Java (R) 303, but is also effective for the application directly executed by the OS 301.

  Further, through the first and second embodiments, the OOB packet data is stored in the IP data and transmitted / received using TCP / IP. However, the present invention can also be implemented using UDP / IP. Moreover, it can be implemented if it can be embedded in a data transmission / reception format other than IP. In addition to the Ethernet, a serial cable may be used.

  Further, although the ADK card 103 is separated from the STB 101 through the first and second embodiments, it can be implemented even if it is built in.

  The present invention is not limited to digital cable television, and can be applied to an application development environment to be executed in a system in which a terminal connects a specific external signal conversion module and communicates with a server via the signal conversion module.

Configuration diagram of Embodiment 1 of a cable television receiving terminal according to the present invention The figure which shows an example of the general view of the ADK card which concerns on this invention 1 is a block diagram showing the configuration of software that operates on a cable television system according to the present invention. The schematic diagram which shows the program component added in order to comprise the application development environment which concerns on this invention, and the relationship of a related program component The schematic diagram which shows the program component which comprises the emulation library based on this invention, and the relationship of a related program component The figure which shows the data format used between the ADK card-OOB server which concerns on this invention Flow chart showing operation of packet decoder Flow chart showing operation of packet encoder Configuration diagram of software that runs on the OOB server Flow chart showing operation of packet decoder Flow chart showing operation of packet encoder Flow chart showing operation of packet encoder A flowchart showing operations of the emulation library 402 and the OOB server library 920 A flowchart showing operations of the emulation library 402 and the OOB server library 920 A flowchart showing operations of the emulation library 402 and the OOB server library 920 The schematic diagram which shows the program component which comprises the emulation library based on this invention, and the relationship of a related program component Flow chart showing operation of packet decoder Configuration diagram of software that runs on the OOB server Configuration diagram of cable television system according to the present invention The figure which shows an example of the usage of the frequency band used for communication between a head end and a terminal device in the cable television system which concerns on this invention The figure which shows an example of the usage of the frequency band used for communication between a head end and a terminal device in the cable television system which concerns on this invention The figure which shows an example of the usage of the frequency band used for communication between a head end and a terminal device in the cable television system which concerns on this invention Configuration of terminal device in cable television system according to the present invention The figure which shows an example of the external appearance of a terminal device in the cable television system which concerns on this invention The block diagram which shows the structure of the built-in program and application in the cable television system which concerns on this invention The figure which shows an example of the application which uses the conventional TCP / IP library

Explanation of symbols

401 card library 402 emulation library 403 switcher 404 OOB SI library 405 socket interface

Claims (15)

In a cable television receiving terminal capable of transmitting and receiving data from the head end in a cable television system via OOB,
An execution means for executing the application;
First receiving means for receiving data output from an OOB server that outputs a second data format different from the first data format transmitted by the head end via OOB;
Conversion means for converting the data in the second data format received by the first reception means into the first data format;
A cable television receiving terminal comprising: a library that provides the application with the data converted by the conversion means. The cable television receiving terminal further includes:
Second receiving means for receiving data transmitted by the head end via the OOB;
2. The cable television receiving terminal according to claim 1, further comprising switching means for switching the first receiving means and the second receiving means to connect to the library. The cable television receiving terminal further includes:
The said 1st receiving means is made into the shape separable from the said cable TV receiving terminal, The said cable TV receiving terminal was provided with the connection means which connects the said 1st receiving means. Cable TV receiver. The cable television receiving terminal further includes:
The first data format is MPEG section data;
The second data format is IP data;
The cable television receiving terminal according to claim 1, wherein the conversion means receives the IP data and converts the IP data into the MPEG section data. The cable television receiving terminal further includes:
The first data format is MPEG section data or first IP data,
The second data format is second IP data, and the second IP data further includes a data format identifier for identifying the format of the data before conversion,
The converting means receives the second IP data, and converts the second IP data into the MPEG section data or the first IP data based on the data format identifier. The cable television receiving terminal according to claim 1. The cable television receiving terminal further includes:
The cable television receiving terminal according to claim 1, further comprising initialization means for establishing a connection with the OOB server. The cable television receiving terminal further includes:
Transmission data generating means for generating data of the second data format based on the second data format;
The cable television receiving terminal according to claim 1, further comprising: a transmission unit configured to transmit data in the second data format generated by the transmission data generation unit to the OOB server. For cable TV receiving terminals that can send and receive data via the OOB from the headend in the cable TV system,
Data generating means for generating a second data format that can be converted to a first data format that the headend transmits via OOB;
An OOB server comprising transmission means for transmitting data generated by the data generation means to the cable television receiving terminal. The OOB server further includes:
9. The OOB server according to claim 8, further comprising initialization means for establishing a connection with the cable television receiving terminal. The OOB server further includes:
9. The OOB server according to claim 8, further comprising conversion means for converting the first data format into the second data format. The OOB server further includes:
The first data format is MPEG section data;
The second data format is IP data;
The OOB server according to claim 10, wherein the conversion means receives the MPEG section data and converts the MPEG section data into the IP data. The OOB server further includes:
The first data format is first IP data;
The second data format is second IP data;
The OOB server according to claim 10, wherein the conversion unit receives the first IP data and converts the first IP data into the second IP data. The OOB server further includes:
Receiving means for receiving data in the second data format;
The OOB server according to claim 8, further comprising: an inverse conversion unit that converts data received by the reception unit into the first data format. A computer-readable recording medium,
In a cable television receiving terminal capable of transmitting and receiving data from the head end in a cable television system via OOB,
An execution means for executing the application;
First receiving means for receiving data output from an OOB server that outputs a second data format different from the first data format transmitted by the head end via OOB;
Conversion means for converting the data in the second data format received by the first reception means into the first data format;
A computer-readable recording medium in which a program that performs each function of a library that provides data converted by the conversion means to the application is recorded. A computer-readable recording medium,
For cable TV receiving terminals that can send and receive data via the OOB from the headend in the cable TV system,
Data generating means for generating a second data format that can be converted to a first data format that the headend transmits via OOB;
A computer-readable recording medium having recorded thereon a program for performing each function of a transmitting means for transmitting data generated by the data generating means to the cable television receiving terminal.

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