JP2001308769A - Satellite digital distribution system and satellite digital distribution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a satellite digital distribution system which can distribute high-capacity digital data at high speed and stably. SOLUTION: The satellite digital distribution system is provided with a database center 1 to accumulate various kinds of digital data, a central control device 2 to control the distribution of the digital data through a satellite communication channel, a satellite repeater 3, a plurality of receiving terminal devices 4 to receive the digital data transmitted through the satellite communication channel, and an access center 5 to perform the transmission and reception of control information between the central control device 2 and the receiving terminal device 4 through the ground-based line. It is not necessary to accumulate the digital data to the receiving terminal device 4 because various digital data accumulated in the database center 1 are distributed to each receiving terminal device 4 through the satellite communication channel. Besides, a notification or the like can be performed reliably and quickly when a receiving error happens because a ground-based line is used for a transmitting confirmation or the like between the central control device 2 and the receiving terminal device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital satellite distribution system and a digital satellite distribution method for distributing music, video and the like using satellite communication.

[0002]

2. Description of the Related Art In recent years, with the rapid development of computer technology, large-capacity digital data such as music and images can be provided relatively easily via communication lines.

[0003] With the progress of such technology, CD (Compa
ct Disc) and other music data have also been launched. For example, JP-A-7-175868 discloses digital information such as music information specified by a customer on a CD.
-R (CD-Recordable) and the like are disclosed. In a system disclosed in this publication, a customer selects desired information using a touch screen or the like at a booth provided at a retail store, and records the selected information on a recording medium such as a CD-R on the spot. Things.

[0004]

As communication means for distributing digital data such as music information, there are a method using a terrestrial line such as a telephone line and a method using a satellite communication line, each having advantages and disadvantages. For example, when using a terrestrial line, stable communication is possible without being affected by natural phenomena, but the disadvantage is that the receiving terminal can be installed only at the place where the terrestrial line is installed, and the communication range is limited. There is. On the other hand, if a satellite communication line is used, communication can be performed over a wide range, and if a parabolic antenna is used, the receiving terminal can be installed at any location. There is a disadvantage that the stability of communication is inferior.

Conventionally, as a technique for distributing a large amount of digital data, a technique using a terrestrial line and a technique using a satellite communication line have been proposed. No optimal method for distributing data has been proposed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a satellite digital distribution system and a satellite digital distribution method capable of rapidly and stably distributing a large amount of digital data. is there.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention provides a database device for storing a plurality of types of digital data, a plurality of receiving terminal devices, and a storage device for storing the digital data. A central management device for controlling the transmission of the digital data to the designated receiving terminal device via a satellite communication line, and between the central management device and the plurality of receiving terminal devices via a satellite communication line. A satellite repeater for transferring the digital data, and a ground line connection unit for transferring control information via a ground line between the central management device and the plurality of receiving terminal devices, The central management device controls transmission of the digital data to the plurality of receiving terminal devices based on the control information.

According to the first aspect of the present invention, a large amount of digital data is transmitted at high speed because digital data is transmitted via a satellite communication line and control information for controlling transmission of the digital data is transmitted via a ground line. And transmission errors occurring during the transmission can be quickly detected.

According to the second aspect of the present invention, since the IP packet data corresponding to the digital data is converted into the TS packet data and transmitted by the frequency division multiplexing method, the communication efficiency can be improved.

According to the third aspect of the present invention, the IP packet data is encrypted, and the key-related TS packet data indicating the key group secretly held in the satellite receiver and the currently used key are transmitted. Since the method of multiplexing and transmitting is adopted, confidentiality of communication can be improved, and it is possible to prevent digital data from being downloaded and reproduced without permission.

According to the fourth aspect of the present invention, before the digital data is distributed, the start signal is transmitted from the central management device to each of the receiving terminal devices, and the reception registration from the receiving terminal device is accepted. Digital data can be delivered to the user, the digital data can be prevented from being missed, and the receiving terminal device that can reliably receive the digital data can be correctly grasped.

According to the fifth aspect of the present invention, when there is a reception error in each receiving terminal device, the block number having the error is notified to the central management device via the terrestrial line. Can be retransmitted, and communication reliability can be improved.

In the invention of claim 6, the IP address registered in advance is
Since only the IP packet data corresponding to the address is transmitted to the data receiving means in the receiving terminal, the confidentiality of the data can be maintained.

According to the invention of claim 7, when there is a reception error,
The central management unit retransmits the data of the erroneous block and reconstructs the file.When the file is completed, a completion signal is sent to the central management unit via the ground line. It is possible to quickly grasp whether or not the distribution has been normally performed.

According to the eighth aspect of the present invention, since a data utilizing terminal device is provided for each receiving terminal device, digital data to be distributed can be arbitrarily selected.

According to a tenth aspect of the present invention, there is provided a satellite digital distribution method for transmitting digital data stored in a database device to a designated receiving terminal device from a plurality of receiving terminal devices via a satellite communication line. A step of transmitting a distribution start signal from the management apparatus to each of the plurality of reception terminal apparatuses via a terrestrial line; and, in response to the distribution start signal, the reception terminal apparatus desiring distribution to the central management apparatus. Transmitting a reception registration signal via a terrestrial line, transmitting the digital data via a satellite communication line to the reception terminal device which has transmitted the reception registration signal from the central management device, Transmitting a reception error signal via a land line from the receiving terminal device detecting the To put al the reception terminal apparatus which has transmitted the reception error signal, comprising the steps of: retransmitting the digital data that caused the reception error through the satellite communication line, a.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a digital satellite distribution system according to the present invention will be specifically described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a satellite digital distribution system according to the present invention. The satellite digital distribution system of FIG. 1 includes a database center 1 for storing various digital data such as music data and video data,
A central management device 2 for controlling distribution of these digital data via a satellite communication line, a satellite repeater 3, a plurality of receiving terminal devices 4 for receiving digital data transmitted via the satellite communication line, An access center (ground repeater) 5 for transmitting and receiving control information to and from the central management device 2 and the receiving terminal device 4 via a ground line is provided.

Each of the receiving terminal devices 4 is provided with a data use terminal 11. As shown in FIG. 2, a selection menu and the like are displayed on the front panel of the data use terminal 11, and a touch panel 1 for selecting distribution data is displayed.
2. A recording medium (for example, M
An insertion slot 13 for inserting a D (Mini Disc) or CD-R, a coin input unit 14 for paying a data distribution fee, a receipt issuing unit 15, and the like are provided.

FIG. 3 is a detailed block diagram showing the internal configuration of the central management device 2 and the receiving terminal device 4. Although only one receiving terminal device 4 is shown in FIG. 3, there are actually a plurality of receiving terminal devices 4 as shown in FIG.

As shown in FIG. 3, the central management device 2 includes a data distribution unit 21 and a satellite distribution unit (satellite distribution means) 22.
And a ground line connection unit 23. Data distribution unit 21
Further, a data storage unit (data storage means) 24 for receiving and storing digital data stored in the database center 1 via a terrestrial line, and transmitting / receiving control information to / from a receiving terminal via a terrestrial line connection unit 23 And a delivery confirmation unit (delivery confirmation means) 25 for performing IP (Inter)
(net protocol) packet data transmitting section (data transmitting means) 26 for transmitting packet data.

The satellite distribution unit 22 further includes a data transmission unit 2
TS (Transport Stream) from the IP packet data from 6
A satellite transmission unit 27 that converts the data into packet data, multiplexes the data with key-related TS packets, performs QPSK modulation, and performs satellite transmission.
And a receiving terminal management unit 28 that manages the receiving terminal device 4 that is the distribution destination.

On the other hand, the receiving terminal device 4 transmits the IP address addressed to its own terminal.
Satellite receiving unit (satellite receiving means) for extracting packet data
31, a data receiving unit (data receiving means) 32 for performing a request for reconstructing or retransmitting a received file, and a terrestrial line connection unit 33.

The data receiving section 32 further includes a data processing section 34 for reconstructing a file, a delivery confirming section 35 for transmitting a reception registration signal and a reception error signal, and a data storage for storing the reconstructed file. A part 36.

FIG. 4 shows a data distribution unit 2 in the central management unit 2.
3 is a flowchart illustrating a processing procedure of No. 1; First, a distribution start signal is transmitted to all the receiving terminal devices 4 via a satellite communication line (step S1). When receiving the distribution start signal, when receiving the digital data, the receiving terminal device 4 transmits a signal requesting the distribution (hereinafter, a reception registration signal) to the central management device 2 via the ground line. The data distribution unit 21 receives the reception registration signal and receives the reception registration from each reception terminal device 4 (Step S).
2). Next, it is determined whether or not the reception registration from all the receiving terminal devices 4 has been completed, or whether or not a predetermined time has elapsed (step S3).

The processing in steps S1 to S3 is performed by the delivery confirmation unit 25 in FIG. When transmitting the delivery start signal, the delivery confirmation unit 25 notifies the name and size of the file to be sent. Therefore, the receiving terminal device 4 can confirm in advance whether or not the data to be distributed can be stored in its own hard disk and whether or not the terminal to be distributed already owns the data to be distributed. It is possible to prevent reception errors due to insufficient distribution and capacity.

If the determination in step S3 is NO, the processes in steps S2 and S3 are repeated. If the determination in step S3 is YES, the data transmission unit 26 divides the file into a plurality of blocks, adds an error detection signal to each of the divided blocks, and transmits the divided blocks to the satellite distribution unit 22 (step S4). This error detection signal is used by the receiving terminal device 4 for error detection for each block.

If each of the receiving terminal devices 4 cannot correctly receive each block data, the receiving acknowledgment (NACK: Not Acknowledgement) signal indicating that there is a transmission error is transmitted via the terrestrial line to the delivery confirmation unit 25. To return. Therefore, the delivery confirmation unit 25 detects whether or not there is a transmission error based on whether or not a negative acknowledgment signal (reception error signal) has been transmitted from the receiving terminal device 4 (step S5).

Next, the data transmission unit 26 is connected to the satellite distribution unit 2
Then, it is determined whether or not transmission of all block data to the block 2 has been completed (step S6). If there is block data that has not been transmitted yet, the processing from step S4 is repeated.

When the transmission of all block data is completed, the data transmission unit 26 retransmits only the block requested to be retransmitted to the receiving terminal that has transmitted the negative acknowledgment signal (reception error signal) (step S12). S7). When each receiving terminal receives all blocks, it returns a completion signal to the data transmitting unit 26.
It is determined whether a completion signal has been received from all receiving terminals or whether a predetermined time has elapsed (step S8).

If the determination in step S8 is NO, the processes in steps S7 and S8 are repeated, and if YES, an end signal is transmitted to the receiving terminal device 4 (step S8).
9).

Data transmission unit 26 in data distribution unit 21
More specifically, multicast distribution to a plurality of reception terminal devices 4, unicast distribution to a single reception terminal device 4, transmission of IP packet data to the satellite distribution unit 22, definition and management of a multicast group, distribution schedule And monitor the file distribution status.

In the flowchart of FIG. 4, step S1 corresponds to the start signal transmitting means, step S3 corresponds to the reception / registration completion determining means, and steps S7 and S8 correspond to the retransmitting means.

FIG. 5 shows a satellite distribution unit 22 in the central management unit 2.
6 is a flowchart showing the processing procedure of FIG. First, the IP packet data transmitted from the data transmission unit 26 is converted into a TS packet for performing satellite communication (step S21). Next, the converted TS packet is multiplexed with a security (key-related) TS packet (step S22). At this time, the IP packet is scrambled for encryption on the satellite line by a TS packetizer that converts the packet into a TS packet. Also, since a PID (Packet ID) is added to the TS packet, only the receiving terminal device 4 corresponding to this PID can be used on the receiving side.
S packet cannot be received.

Next, TS packets multiplexed with key-related TS packets are converted into QPSK (Quadrature Phase Shift Keying).
Modulated by a modulator, FDM (Frequency Division Multiple
(x: frequency division multiplexing) method to transmit to the receiving terminal device 4 via the satellite communication line (step S23).

In the flowchart of FIG. 5, step S21 corresponds to the TS packet converting means, step S22 corresponds to the multiplexing means, and step S23 corresponds to the FDM transmitting means.

Receiving terminal management unit 28 in satellite distribution unit 22
Performs reception terminal information management, receiver information management, key information management, and reception terminal state investigation.

The reception terminal information management is, specifically, management of the name, installation location, installation date, reception terminal ID, and the like of the reception terminal device 4.

More specifically, the receiver information management includes the ID, PID, and MAC (Multimedia Access C) of the receiving terminal device 4.
ontrol) address, IP address, netmask, reception frequency, polarization, satellite name, symbol rate, LNB local frequency, and routing table management.

The key information management includes receiving terminal ID, PID,
This is management of a PID for an EMM (Entitlement Management Message), a master key (Km), and a session key (Ks).

In the receiving terminal state investigation, specifically, the internal state and setting information of the receiving terminal apparatus 4 having no registration response or the receiving terminal apparatus 4 having many reception errors are investigated via the terrestrial line, and if necessary. To change the settings.

The satellite transponder 3 relays data transmitted via a satellite communication line by a frequency division multiplex system.
Here, the communication cost is reduced by using only the frequency band and the output power required for digital data distribution.

FIG. 6 shows the data receiving unit 3 in the receiving terminal device 4.
6 is a flowchart illustrating a processing procedure of No. 2; First, a distribution start signal sent from the central management device 2 via the satellite communication line is received (step S41). Next, if the own receiving terminal device (own terminal) 4 can receive, the reception registration signal is sent to the delivery confirmation unit 25 of the central management device 2 via the ground line (step S42). On the other hand, when the terminal 4 is not operating, when the terminal 4 is not connected to the satellite communication line, or when there is not enough hard disk capacity to store the digital data to be distributed, the reception registration signal is not sent.

Next, the IP data received by the satellite receiving section 31 is taken in, and the transmitted file is reconstructed (step S43). Next, it is determined whether a reception error has occurred (step S44). If there is a reception error,
The block number having the error is notified to the central management unit 2 via the terrestrial line (step S45). When it is determined that there is no reception error in step S44, or in step S45.
Is completed, the block containing the reception error is left empty, and a temporary file is constructed (step S46). If a block that has been retransmitted afterwards is correctly received, the block is refilled into a vacant portion.

If the file is not completed yet, the processing from step S43 is repeated, and when the file is completed,
A completion signal is transmitted to the central management device 2 via the ground line (step S48).

In the flowchart of FIG. 6, step S41 is a start signal receiving means, step S42 is a reception registration means, steps S43 and S44 are reception error determination means, step S45 is a reception error notification means, and step S47 is completion. Each corresponds to signal transmission means.

FIG. 7 shows a satellite receiving unit 31 in the receiving terminal device 4.
6 is a flowchart showing the processing procedure of FIG. First, FDM
The wave is received and QPSK demodulation is performed (step S61). next,
The TS packet corresponding to its own receiving terminal device 4 is extracted (step S62). Next, IP data is reconstructed from the extracted TS packets (step S63). Next, IP
The encryption (scramble) of the data is decrypted, and the IP data is restored (step S64). Next, the previously registered IP
The data receiving unit 32 receives only the IP data corresponding to the address.
(Step S65).

In the flowchart of FIG. 7, step S61 corresponds to demodulation means, step S62 corresponds to TS packet extraction means, step S63 corresponds to reconstruction means, step S64 corresponds to decoding means, and step S65 corresponds to IP selection means. I do.

As described above, in this embodiment, various digital data stored in the database center 1 are distributed individually or simultaneously to a plurality of receiving terminal devices 4 via a satellite communication line. There is no need to accumulate digital data in the device 4, and the digital data can be distributed to a large number of receiving terminal devices 4 at extremely low cost.

Also, when adding or deleting digital data, only the digital data in the database center 1 needs to be updated, and the receiving terminal device 4 does not need to make any changes. Will not start.
Further, it is possible to easily add the receiving terminal device 4.
At that time, digital data can be received only by providing a small satellite dish for satellite communication, so that installation cost can be reduced.

Further, the central management device 2 and the receiving terminal device 4
When exchanging control information, such as transmission confirmation, with a terrestrial line such as a telephone line, control information can be exchanged irrespective of digital data distribution, and notification when a reception error occurs, etc. Can be performed reliably and quickly, and the reliability of communication is improved.

The digital data stored in the database center 1 in FIG. 1 is not particularly limited, and covers all data that can be transmitted via a satellite communication line. In the above-described embodiment, an example in which digital data selected by the data use terminal 11 is distributed from the database center 1 has been described. However, even when digital data is not selected by the data use terminal 11, at least one The data may be unilaterally distributed to the receiving terminal device 11.

In the above-described embodiment, an example has been described in which digital data is transmitted by frequency division multiplexing (FDM). However, the format of data transmitted via a satellite communication line is not particularly limited. It may be transmitted by a spread method. Further, the modulation scheme is not limited to QPSK, and a multi-level frequency modulation (MFSK) scheme, a multi-level phase modulation (MPSK) scheme, or the like may be employed.

[0054]

As described above in detail, according to the present invention, various digital data stored in the database device are distributed individually or simultaneously to a plurality of receiving terminal devices via a satellite communication line. Therefore, it is not necessary to store digital data in the receiving terminal devices, and the digital data can be distributed to a large number of receiving terminal devices at extremely low cost.

When control information such as transmission confirmation is exchanged between the central management unit and the receiving terminal device, a ground line such as a telephone line is used, so that the control information is transmitted independently of digital data distribution. The communication can be performed, and a notification or the like when a reception error occurs can be performed reliably and promptly, and the reliability of communication is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a satellite digital distribution system according to the present invention.

FIG. 2 is an external view of a data use terminal.

FIG. 3 is a detailed block diagram showing an internal configuration of a central management device and a receiving terminal device.

FIG. 4 is a flowchart showing a processing procedure of a data distribution unit in the central management device.

FIG. 5 is a flowchart showing a processing procedure of a satellite distribution unit in the central management device.

FIG. 6 is a flowchart illustrating a processing procedure of a data receiving unit in the receiving terminal device.

FIG. 7 is a flowchart showing a processing procedure of a satellite receiving unit in the receiving terminal device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Database center 2 Central management device 3 Satellite repeater 4 Receiving terminal device 5 Access center 11 Data utilization terminal 12 Touch panel 13 Recording medium insertion port 14 Coin input unit 15 Receipt issuing unit 21 Data distribution unit 22 Satellite distribution unit 23, 33 Ground line Connection unit 24 Data storage unit 25, 35 Delivery confirmation unit 26 Data transmission unit 27 Satellite transmission unit 28 Reception terminal management unit 31 Satellite reception unit 32 Data reception unit 34 Data processing unit 36 Data storage unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court II (Reference) H04L 12/56 (72) Inventor Kazuhiko Hashimoto 3-3-13 Kitaaoyama, Minato-ku, Tokyo Kyowa Gobankan Building 5F Nippon Business Television Co., Ltd. F-term (reference) 5K030 GA11 GA20 HA05 HB01 HB02 JL02 KA07 KA17 LA01 LD06 5K072 AA23 AA24 BB02 BB04 BB13 BB22 DD02 DD16 DD17 DD19 EE06 FF10 FF22 FF27 9A001 CC02 EK56 JJ13

Claims (10)

[Claims] A database device for storing a plurality of types of digital data; a plurality of receiving terminal devices; and a digital data stored in the database device.
A central management device that controls transmission to the designated receiving terminal device via a satellite communication line, between the central management device and the plurality of receiving terminal devices,
A satellite transponder that transmits and receives the digital data via a satellite communication line, between the central management device and the plurality of receiving terminal devices,
A ground repeater for transmitting and receiving control information via a ground line, wherein the central management device controls transmission of the digital data to the plurality of receiving terminal devices based on the control information. Satellite digital distribution system. 2. The central management device: data storage means for extracting the digital data to be delivered from the database device via a terrestrial line and storing the digital data; dividing the digital data into a plurality of blocks; IP (Internet Prot)
ocol) data transmission means for generating and transmitting packet data; transmission confirmation means for receiving a negative acknowledgment signal based on the result of error detection for each block transmitted from the receiving terminal device; and transmission from the data transmission means. Satellite distribution means for converting the converted IP packet data into TS (Transport Stream) packet data, and transmitting the converted TS packet data to the designated receiving terminal device via a satellite communication line in a frequency division multiplexing system 2. The satellite digital distribution system according to claim 1, comprising: 3. The satellite distribution means: TS packet conversion means for encrypting the IP packet data transmitted from the data transmission means and converting the IP packet data into TS packet data; Multiplexing means for multiplexing the TS packet data; and QPSK (Quadrature Phase Shift Ke
3. The digital satellite distribution system according to claim 2, further comprising: FDM transmitting means for performing ying) modulation and transmitting the modulated data through a satellite communication line by a frequency multiplexing method. 4. The acknowledgment means is responsive to a distribution start signal transmitted by the data transmission means to each of the plurality of receiving terminal apparatuses, and transmitted from the receiving terminal apparatus which desires distribution via a ground line. Receiving the received reception registration signal, the data transmitting means, before performing the distribution of the digital data, a start signal transmitting means for transmitting the distribution start signal to each of the plurality of receiving terminal devices; The reception registration completion determining means for determining whether or not the reception registration of all the terminal devices is completed, and transmitting the IP packet data after the completion, and a transmission error for the reception terminal device which transmitted the negative acknowledgment signal. The digital satellite distribution according to claim 2, further comprising: retransmission means for retransmitting the IP packet data corresponding to the block having the error. system. 5. Each of the receiving terminal devices demodulates a received wave transmitted from the central management device via a satellite communication line, and reconstructs the IP packet data. If the digital data can be received when the distribution start signal is transmitted from the management device via the satellite communication line, a reception registration signal is transmitted to the central management device via the ground line if the digital data can be received. After that, if there is a reception error in the IP packet data transmitted from the central management device via the satellite communication line and reconstructed by the satellite receiving means, the identification number of the erroneous block is transmitted via the ground line. 5. The satellite digital distribution system according to claim 4, further comprising: a data transmission unit that transmits the data to the central management device. 6. The satellite receiving means includes: a demodulating means for performing QPSK demodulation of a received wave transmitted from the central management device via a satellite communication line; and a TS for extracting TS packet data corresponding to the own receiving terminal. Packet extracting means, reconstructing means for reconstructing IP packet data from the extracted TS packet data, decrypting means for decrypting the encryption of the reconstructed IP packet data, and IP packet data corresponding to a pre-registered IP address The satellite digital distribution system according to claim 5, further comprising: an IP selecting unit that transmits only the data to the data receiving unit. 7. The data receiving means includes: a start signal detecting means for receiving the distribution start signal transmitted from the central management device via a satellite communication line; and a start signal detecting means capable of receiving the digital data by itself. For example, reception registration means for transmitting a reception registration signal to the central management device via a ground line, and reception of IP packet data transmitted from the central management device via a satellite communication line and reconstructed by the satellite reception means Receiving error determining means for determining whether there is an error; receiving error notifying means for transmitting an erroneous block number to the central management unit via a terrestrial line if there is a receiving error; 7. A completion signal transmitting means for transmitting a completion signal to the central management device via a ground line when the file is completed, and a completion signal transmitting means. Digital distribution system. 8. A data use terminal device provided for each of said receiving terminal devices and capable of arbitrarily selecting digital data desired to be distributed among said digital data stored in said database device, Transmitting a digital data distribution request signal selected by the data use terminal device to the central management device via a terrestrial line, the satellite digital distribution device according to any one of claims 1 to 7, wherein system. 9. The system according to claim 1, wherein said database device stores at least a plurality of types of music data.
A satellite digital distribution system according to any one of claims 1 to 8. 10. A satellite digital distribution method for transmitting digital data stored in a database device to a designated receiving terminal device from a plurality of receiving terminal devices via a satellite communication line. Transmitting a distribution start signal via a satellite communication line to each of the receiving terminal devices, and in response to the distribution start signal, from the receiving terminal device that desires distribution to the central management device, a ground line. Transmitting a reception registration signal via a satellite communication line to the reception terminal device which has transmitted the reception registration signal from the central management device; and Transmitting a negative acknowledgment signal via a land line from the receiving terminal device to the central management device; To transmitting the negative acknowledgment signal the receiving terminal apparatus, the satellite digital distribution method characterized by comprising the steps, the retransmitting the digital data that caused the reception error through a satellite communication line.