JP3887945B2 - Data receiving apparatus and data receiving method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data receiving apparatus and a data receiving method for outputting digital data received via, for example, a digital satellite broadcasting line to a computer.
[0002]
[Prior art]
A receiving device that can receive only a stream of broadcast audio data or video data and output an audio / video stream from an external interface, such as a receiving device for cable television broadcasting or satellite broadcasting, is generally used. ing.
[0003]
Some of such receiving apparatuses have a function of receiving digital data used on a computer in addition to a video / audio stream, and the data stream can be output from an output port to a computer or the like. However, such a receiving apparatus is not provided with a function of outputting received broadcast data as an IP (Internet Protocol) datagram.
[0004]
[Problems to be solved by the invention]
For this reason, in order to use the data received via the broadcast line by the computer, it is necessary to attach a dedicated circuit board to each computer, which is not versatile and not always easy to use.
[0005]
The present invention has been made to solve such problems. For example, a data receiving apparatus capable of converting digital data sent via a digital satellite broadcasting line or the like into an IP datagram and outputting it to a computer or the like. And providing a data receiving method.
[0006]
The data receiving apparatus of the present invention proposed to solve the above-described problem is a data receiving apparatus that receives broadcast data including digital data and outputs the broadcast data to a computer. Because Broadcast data is input Have an address assigned on the broadcast line A first interface; a packetizer for reconfiguring the input broadcast data into predetermined packets; and a second interface for outputting the reconfigured packet to a computer A third interface for connecting to the Internet, and route selecting means for selecting a route between the first to third interfaces, the route selecting means being connected to the computer on the Internet An address conversion table for converting the assigned address and the address of the first interface; It is characterized by this.
[0007]
The data receiving method of the present invention proposed to solve the above-mentioned problem is a data receiving method for receiving broadcast data including digital data and outputting it to a computer. By receiving broadcast data including digital data requested from the computer A packetizing step of reconstructing the input broadcast data into a predetermined protocol packet, and when outputting the reconfigured predetermined protocol packet to a computer, The packet address is changed from the address of the broadcast interface assigned on the broadcast line of the broadcast data to the address of the computer. Rewrite , And a route selection step for controlling a data route.
[0008]
According to the present invention described above, it is possible to provide a data receiving apparatus and a data receiving method for converting data sent via a broadcast line into IP data and outputting it to a computer.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, a preferred embodiment of the present invention will be described with reference to the drawings. In the following, first, the basic configuration and operation of the data receiving apparatus according to the present invention will be described, and further specific examples thereof will be described.
[0010]
FIG. 1 is a diagram showing an external appearance of an embodiment of a data receiving apparatus of the present invention, and FIG. 2 is a block diagram showing a configuration of a main part of the data receiving apparatus of the present invention.
[0011]
These data receiving apparatuses shown in FIGS. 1 and 2 receive digital data used in computers and the like in addition to functions as ordinary broadcast receiving apparatuses that receive and output streams of video data and audio data. have. The data receiving apparatus includes an external output interface for outputting a stream of received video data, audio data, and digital data.
[0012]
Specifically, the data receiving apparatus 101 according to the present invention includes a broadcast interface 1a connected to a broadcast line via a terminal 1 via a coaxial cable or the like, and a personal computer via a terminal 2 to a LAN (local area network). A PC (Personal Computer) interface 2a for connection to the telephone 20, a telephone interface 3a for connection to an external network such as the Internet via a telephone line connected to the terminal 3, and the received A / V (audio / video) ) An AV equipment interface 4a for outputting data via the terminal 4 is provided.
[0013]
The data receiving apparatus 101 is characterized in that it is configured compactly by accommodating the above-described interfaces, which have conventionally been configured on a circuit board mounted in an expansion slot or the like of the computer 20, in the same housing. It is. For this reason, the data receiving apparatus 101 is installed between the computer 20 and the broadcast line or telephone line, and the connector 20 is connected, so that the data sent via the broadcast line can be converted into IP data and used by the computer 20. It becomes like this.
[0014]
The basic function of this data receiving apparatus is to receive digital data sent via a large-capacity one-way line such as a satellite broadcast line and output it to a computer. For this purpose, the data transmission / reception apparatus includes three interfaces.
[0015]
The broadcast interface 1a, which is the first interface, is a broadcast receiving interface that is connected to a broadcast line via a terminal 1 through a coaxial cable or the like, such as a tuner unit 10 for receiving satellite broadcasting or cable television broadcasting. It is comprised including. The broadcast line to be connected is not limited to the satellite broadcast and cable television broadcast described above, but may be a broadcast line using terrestrial waves.
[0016]
The PC interface 2a as the second interface is a personal computer interface for transmitting and receiving data to and from the computer via the terminal 2. Usually, it is configured to include a LAN interface for connecting to a computer via a local area network (LAN). The assumed LAN is 10BaseT that performs baseband transmission at a transmission rate of 10 Mbps, or IEEE 1394 Standard that can transmit a mixture of control signals and information signals at a serial interface standard at a transfer rate of 100 M / 200 M / 400 Mbps. It is based on standards such as for a High Performance Serial Bus.
[0017]
The telephone interface 3a as the third interface is an external connection interface for connecting to an external network such as the Internet. As the telephone line, PSTN (Public Switched Telephone Network) that transmits an analog voice signal in the 3.4 kHz band and ISDN (Interated Services Digital Network) that transmits digital data at 64 to 128 kbps are used. These telephone lines are connected to the terminal 3 via a modem or ISDN (Interated Services Digital Network) terminal adapter.
[0018]
Note that this data receiving apparatus may be configured to include only the broadcast interface 1a and the PC interface 2a depending on the required functions. In addition to the above interfaces, an ATM (Asynchronous Transfer Mode), an optical fiber distributed data interface (FDDI), or the like may be used.
[0019]
The tuner unit 10 selects a desired broadcast channel from broadcast data input via the terminal 1 and outputs a data stream (data string). This data stream includes digital data used on a computer in addition to audio data and video data.
[0020]
A demultiplexer 11 collects and distributes packets having the same packet identifier (PID) among the packets of the data stream selected by the tuner unit 10. As a result, the audio data, video data, and digital data that have been multiplexed into broadcast data are separated from each other.
[0021]
The audio data and video data separated here are sent to the A / V decoder 16, and the digital data is sent to the packetizer 12 described later.
[0022]
The A / V decoder 16 is for decoding the video data and audio data streams from the demultiplexer 11 into analog signals. This analog signal is output from the A / V output terminal 4.
[0023]
Next, the data receiving apparatus will be further described along the flow of digital data separated by the demultiplexer 11.
[0024]
In the following description, it is assumed that a personal computer connected via the PC interface 2a is connected to a service provider on the Internet via the telephone interface 3a. Also, assume that each of the above interfaces is assigned an Internet Protocol (IP) address, and the data stream is an IP datagram.
[0025]
As described above, the stream of digital data separated by the demultiplexer 11 is sent to the packetizer 12. The packetizer 12 is for, for example, converting a transport stream packet unit or format based on the transmission standard of the digital satellite method to generate a predetermined packet based on, for example, the Internet protocol.
[0026]
Here, for example, a transport stream packet (TS packet) from the demultiplexer 11 is reconstructed into an Internet protocol packet (IP packet) and sent to the route selection unit 13. An IP packet as a set of data is also called an IP datagram.
[0027]
The route selection unit 13 is for selecting a route of data exchanged via the data receiving device and converting a destination address according to the selected route. A path between 1a and the PC interface 2a and the telephone interface 3a is selected. The control information may be included in broadcast data input via the broadcast interface 1a, or may be included in data transmitted from a personal computer connected via the PC interface 2a.
[0028]
The LAN interface 14 is an interface for transmitting / receiving data to / from a personal computer connected via the terminal 2, and is an interface for connecting to a local area network (LAN).
[0029]
The modem 15 is an interface for transmitting / receiving data to / from an external network via a telephone line connected to the terminal 3. A terminal adapter is used when the telephone line is an ISDN line.
[0030]
The billing control unit 17 is for controlling billing when receiving a pay broadcast program called CA (Conditional Access) control, and is provided as necessary. The billing control unit 17 has a function of transmitting billing information generated according to, for example, conditions recorded on a memory card to a broadcaster or the like via a telephone line.
[0031]
In the above description, it is assumed that the broadcast data input to the data receiving device is not scrambled, but the actual broadcast data is usually scrambled. In this case, a descrambler for audio / video data is arranged after the tuner unit 10, and a descrambler for data is arranged after the packetizer 12.
[0032]
Next, the operation of the data receiving apparatus of the present invention having the above basic configuration will be described with reference to FIG.
[0033]
First, a case where IP datagrams are transmitted and received between a personal computer and an external Internet connection provider via the data receiving apparatus will be described.
[0034]
The IP datagram received via the terminal 2 constituting the PC interface 2 a and the LAN interface 14 is sent to the route selection unit 13. When this IP datagram is sent to the telephone line side, the telephone interface 3a is selected here and the data is sent to the modem 15. Then, the modem 15 makes a call to the Internet connection provider via the telephone line connected to the terminal 3 and, when the connection operation is completed, sends out an IP datagram from the terminal 3 to the telephone line.
[0035]
In addition, data sent from the Internet connection provider via the telephone line is input to the route selection unit 13 from the terminal 3 via the modem 15. Here, the PC interface 2a is selected, and the received data is output to the computer.
[0036]
Here, a standard Internet protocol is used as a communication protocol when an IP datagram is output from the route selection unit 13 through the PC interface 2a. In addition, this data receiving device is connected to each receiving device in the process of PPP (Point-to-Point Protocol) connection with an Internet connection provider in advance. Connected to Personal computer In It is assumed that the assigned IP address has been acquired. Furthermore, after obtaining the IP address, the authentication server managed by the digital satellite broadcaster on the Internet is accessed to obtain the IP address assigned to each receiving device used on the broadcast line. The correspondence between the upper IP address and the IP address on the broadcast line is stored in the memory (RAM) in the route selection unit 13 as the address conversion table 13a.
[0037]
Next, when sending a request from the computer to an external network such as the Internet, a two-way telephone line is used, and the data from the Internet in response to the above request is stored in a large capacity such as a digital satellite line or a cable television broadcasting line. Data when receiving using a one-way broadcast line will be described.
[0038]
As shown in FIG. 3A, a request from the personal computer is sent to the route selection unit 13 via the PC interface 2a. At this time, the route selection unit 13 rewrites the IP data address in the header portion of the IP datagram to the IP address of the broadcast interface 1a based on the address conversion table 13a. The IP datagram whose IP address has been rewritten is sent to the Internet side from the telephone line via the modem 15 after the checksum is recalculated. Here, the rewritten IP address pair is stored in the address conversion table 13a. That is, this address conversion table 13a shows the correspondence between the IP address used on the broadcast line and the IP address used on the normal Internet.
[0039]
By performing this address conversion, as shown in FIG. 3B, the data transmitted from the Internet server passes through a broadcasting line such as digital satellite broadcasting, and the broadcasting interface 1a of the data receiving apparatus The data is received by the personal computer via the multiplexer 11, the packetizer 12, the path selection unit 13, and the PC interface 2a. That is, the transport stream packet received by the tuner unit 10 via the broadcast interface 1 a is converted into an IP packet by the packetizer 12 and sent to the route selection unit 13. Here, the IP destination (destination) address assigned on the broadcast line in the header portion of the IP packet or IP datagram is rewritten to the IP address of the computer that made the request for the data. Then, the PC interface 2a is selected and an IP datagram is sent to the personal computer.
[0040]
Note that the bidirectional communication using the broadcast interface 1a of the data receiving device is not limited to the method realized by the above address rewriting, and can be realized by various methods.
[0041]
Next, an IP packet will be described.
FIG. 4 shows the configuration of the IP packet.
[0042]
The size of the IP packet 60 is defined by TCP / IP (Transmission Control Protocol / Internet Protocol), and when the data requested by the user exceeds the size, the data is divided into a plurality of IP packets.
[0043]
When data is encrypted, it is usually performed on 64-bit plaintext. When the data length of the IP packet 60 to be encrypted is not a multiple of 64 bits, By padding invalid data, the entire IP packet 60 is made a multiple of 64 bits to be an IP packet 61.
[0044]
A MAC header 70 is added to the IP packet 62 in which the IP packet 61 for a specific user is encrypted. The MAC header 70 is composed of a total of 64 bits including an 8-bit SSID (Server System ID), a 24-bit UDB (User Depend Block) 1, and a 32-bit UDB2. In particular, in the UDB 2 of the MAC header 70, a transmission destination IP address similar to the transmission destination IP address written in the IP header is written.
[0045]
The destination IP address in the IP header is encrypted, and the receiving device cannot know the destination IP address without decrypting the cipher, but the MAC header 70 has the same destination IP address. For example, the receiving side can know whether it is a data block addressed to itself by simply reading it out in hardware.
[0046]
The UDB 1 includes a 3-bit PBL (Padding_Byte_Length), a 1-bit CP (Control_Packet), a 1-bit EN (Encrypted_or_Not), a 1-bit PN (Protocol_Type Available_or_Not), a 2-bit Reserve, A 16-bit protocol number (Protocol Type) is set.
[0047]
Of these, PBL is the padding byte length, and is the length of invalid data that has been compensated for during encryption. This is necessary for the user who receives the encrypted IP packet to know the proper data length.
[0048]
The CP is a bit for identifying whether the IP packet contains data required by the user or control data required for system operation. Normally, the CP of the MAC frame 63 to be received when the user makes a request indicates that data is contained instead of control data.
[0049]
EN is a control bit indicating whether or not the IP packet is encrypted by the encryptor. Based on this bit information, the user decides whether or not to decode the received MAC frame 63. The PN is a control bit indicating whether there is useful information in the Protocol Type area. The above control bits are added to the IP packet 62.
[0050]
Here, in addition to the transmission destination IP address, a content ID indicating the type of IP packet information may be set in the UDB 2. This content ID will be described later. It is the SSID that identifies whether the destination IP address or the content ID is set in the UDB 2.
[0051]
A CRC (Cyclic Redundancy Checking) is added to the MAC frame 63. By calculating the CRC on the data transmission side in this way, the data reception side can check whether the received MAC frame is correctly transmitted. The generated 16-bit CRC is added to the end of the MAC frame 63.
[0052]
The MAC frame 63 is converted into a section defined by MPEG2, for example. The MAC frame 63 is added immediately after the section (Sec) header 71 and is called a private section 64.
[0053]
The private section 64 to be transmitted is divided into transport packets 651, 652,.
[0054]
FIG. 5 shows the IP header of the IP packet 60 used here. This IP header contains the user's destination IP address 74 and the source IP address 73. This destination IP address 74 is 32 bits.
[0055]
Next, the data receiving apparatus as an embodiment of the present invention will be described more specifically.
[0056]
FIG. 6 is a block diagram showing a specific configuration example of the data receiving apparatus according to the present invention.
[0057]
Data transmitted via a broadcast line in response to a request from a specific user is received by the receiving antenna 31 on the user side and transferred to the data receiving device of the specific user.
[0058]
A signal received by the receiving antenna 31 is converted into an IF signal and input from the terminal 1 to the data receiving device 32. In the data receiving device 32, it is converted into a digital signal through a tuner 33, an A / D converter 34, a demodulator 35 and a decoder 36. Here, the microcomputer 51 controls the operations of the demodulator 35 and the decoder 36 in accordance with instructions from the CPU 42.
[0059]
Then, it is sent to the descrambler 37 as TS packet data which has been subjected to demodulation processing and error correction processing and encrypted.
[0060]
The descrambler 37 performs descrambling processing at the TS packet level on the encrypted TS packet data. In this case, the descrambler 37 reads the values of the PID part and the scramble control part from the header part of the encrypted TS packet data, and determines whether the TS packet decryption key corresponding to these values is given by the service provider. . If a decryption key is given, the payload portion of the encrypted TS packet is decrypted with the decryption key and output. On the other hand, if the decryption key is not given, the encrypted TS packet is discarded.
[0061]
The decoded TS packet is supplied to the demultiplexer 38. The demultiplexer 38 divides the audio data and the video data multiplexed together with the TS packet data, supplies the audio data to the audio decoder 39, and supplies the video data to the video decoder 40. The audio decoder 39 outputs an analog audio signal from the audio output terminal 4a, and the video decoder 40 outputs an analog video signal from the video output terminal 4b via the NTSC encoder 41. The remaining TS packet data is supplied to the packetizer 45.
[0062]
The packetizer 45 is for reconstructing TS packets from the demultiplexer 38 into Internet protocol packets (IP packets). The reconstructed IP packet (IP datagram) is sent to the route selection unit 47 via the data descrambler 46. The data descrambler 46 is for performing descrambling processing when the IP datagram is scrambled. The decryption key at this time is stored in the dual port RAM (DPRAM) 48 in association with the identifier.
[0063]
The route selection unit 47 is a means for selecting whether the IP datagram is output to a computer via the LAN interface 49 or sent to an external network connected via a telephone line via the modem 54. This operation is controlled by the CPU 42 as control means.
[0064]
The CPU 42 is a control unit that controls the operation of the data receiving apparatus. Specifically, the setting of the value of the reference table is controlled together with the reading of the DPRAM 48, and the demultiplexer 38 and the DPRAM 48 are controlled according to the program read from the ROM 44 to the RAM 43. The CPU 42 also performs control to transmit the request to an external network via the modem 54 and a telephone line. These controls are performed via the host bus 55.
[0065]
Further, the CPU 42 may process the data read from the IC card reader 53 so as to generate the decryption key or generate billing information as necessary.
[0066]
Finally, the shape of the data receiving apparatus of the present invention will be described.
[0067]
This data receiving apparatus is housed in a box-shaped housing as described above, and has a broadcast interface for connecting to a broadcast line on its back surface, a computer interface for connecting to a LAN, etc., and a telephone line. An external connection interface is provided. The data receiving apparatus has a broadcast receiving function similar to that of a commercially available broadcast receiving apparatus.
[0068]
FIG. 7 shows an example of the configuration of the front panel of the data receiving apparatus.
[0069]
The front panel is provided with an indicator that indicates an operating state. In this example, a power indicator 80 that indicates a power on / off state, a link indicator 85 that indicates a link state, and a data co-region (collision). A collion indicator 87 is provided to indicate that has been detected.
[0070]
FIG. 8 shows another configuration example of the front panel of the data receiving apparatus.
[0071]
In this example, in addition to the indicators illustrated in FIG. 7, a B1 indicator 81, a B2 indicator 82, a Tx (transmission) indicator 83, an Rx (reception) indicator 84, and an analog indicator 86 are provided.
[0072]
FIG. 9 shows still another configuration example of the front panel of the data receiving apparatus. In this example, a power indicator 80, a Tx indicator 83, an Rx indicator 84, a link indicator 85, an analog indicator 86, and a collocation indicator 87 are provided.
[0073]
FIG. 10 shows a configuration example of the back panel of the data receiving apparatus.
[0074]
Various terminals (connectors) serving as interfaces are provided on the rear panel, and a computer is connected via a tuner interface (Tuner I / F) connector 91 for connecting a broadcast line and a tuner unit, a LAN, and the like. For this purpose, a network interface (Network I / F) connector 92 and a telephone interface (telephone I / F) connector 93 for connecting to a telephone line via a modem or the like are provided. These connectors 91, 92, and 93 correspond to the terminals 1, 2, and 3 in FIGS.
[0075]
Also, audio R / L output connectors 94A and 94B for outputting analog audio signals, video output connectors 95A and 95B for outputting analog video signals, and S for outputting video signals. Video (S Video) output connectors 96A and 96B are provided. The power connector 100 is for supplying power to the data receiving apparatus.
[0076]
【The invention's effect】
According to the present invention, a first interface to which broadcast data is input, a packetizer that reconfigures the input broadcast data into predetermined packets, and a second interface that outputs the reconfigured packets to a computer. Since it is configured to receive data sent via a broadcast line, convert it into an IP packet that can be processed centrally by a personal computer, for example, and output it, the telephone line from each user's personal computer via the telephone line Data transmitted via the broadcast line in response to the request can be used on the computer.
[0077]
In addition, since the IP address assigned on the Internet and the IP address assigned on the broadcast line are automatically converted, the user can access the Internet without being aware of the difference between these IP addresses.
[0078]
In addition, since the means for realizing the above functions are compactly housed in the same housing and equipped with all necessary interfaces, a highly versatile data receiving apparatus without being restricted by the type of computer or the like Can be offered as. By using this data receiving apparatus, a large-capacity one-way line such as a digital satellite broadcast line can be easily used when a large amount of data is downloaded at high speed from an external network such as the Internet.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a data receiving apparatus according to the present invention.
FIG. 2 is a block diagram showing a configuration of a main part of a data receiving apparatus according to the present invention.
FIG. 3 is a diagram for explaining the flow of data in the data receiving apparatus according to the present invention.
FIG. 4 is a diagram for explaining a process of creating an IP packet.
FIG. 5 is a diagram showing a detailed configuration of an IP header.
FIG. 6 is a block diagram showing a specific configuration example of a data receiving apparatus according to the present invention.
FIG. 7 is a diagram showing a configuration example of a front panel of a data receiving apparatus according to the present invention.
FIG. 8 is a diagram showing another configuration example of the front panel of the data receiving apparatus according to the present invention.
FIG. 9 is a diagram showing still another configuration example of the front panel of the data receiving apparatus according to the present invention.
FIG. 10 is a diagram illustrating a configuration example of a back panel of a data receiving device according to the present invention.
[Explanation of symbols]
1, 2, 3, 4 terminals, 10 tuner section, 11 demultiplexer, 12 packetizer, 13 route selection section, 13a address conversion table, 14 LAN interface, 15 modem, 16 A / V decoder, 17 charging control section

Claims (10)

A data receiving device that receives broadcast data including digital data and outputs the broadcast data to a computer ,
A first interface having broadcast data input and an address assigned on the broadcast line;
A packetizer for reconfiguring the input broadcast data into predetermined packets;
A second interface for outputting the reconstructed packet to a computer ;
A third interface for connecting to the Internet;
Route selection means for selecting a route between the first to third interfaces,
The data receiving apparatus according to claim 1, wherein the route selection means has an address conversion table for converting an address assigned to the computer on the Internet and an address of the first interface .   2. The data receiving apparatus according to claim 1, wherein the broadcast data is input via a satellite broadcast line or a cable television broadcast line.   2. The data receiving apparatus according to claim 1, wherein the predetermined packet to be reconfigured is an Internet protocol packet.   2. The data receiving apparatus according to claim 1, wherein the second interface is an interface for connecting to a local area network, and the reconfigured packet is output to a computer via the local area network. .   2. The data receiving apparatus according to claim 1, wherein the second interface is an interface based on IEEE1394 Standard for a High Performance Serial Bus. The route selection means includes an address assigned on the Internet of a request packet input from the computer for requesting data supply using a broadcast line of the first interface assigned on the broadcast line. It is converted into an address, sent to the Internet side via the third interface, broadcast data is received at the first interface via the broadcast line in response to the request, and reconfigured by the packetizer 2. The data receiving apparatus according to claim 1 , wherein the address of the received packet is converted into an address assigned on the Internet and sent to the computer via the second interface . A data receiving method for receiving broadcast data including digital data and outputting it to a computer ,
A packetizing step of reconfiguring broadcast data input by receiving broadcast data including digital data requested from the computer into a predetermined protocol packet;
When outputting the reconfigured predetermined protocol packet to the computer, the address of the packet is rewritten from the address of the broadcast interface assigned on the broadcast line of the broadcast data to the address of the computer to control the data path And a route selection step. 8. The data receiving method according to claim 7 , wherein the broadcast data is input via a satellite broadcast line or a cable television broadcast line. 8. The data receiving method according to claim 7 , wherein the reconstructed predetermined packet is an Internet protocol. Has an interface to connect to the Internet,
In the route selection step, when requesting data supply using the broadcast data from the computer, the address of the request packet is converted from the address of the computer to the address of the broadcast interface of the broadcast data, 8. The data receiving method according to claim 7, wherein the data receiving method is sent to the Internet side.

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