JP2003134075A - Data distribution system, transmitting station and terminal station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that utilization efficiency of a frequency band is poor, in addition, structure of a transmitting station and a receiving station becomes complicated to bring about extra costs. SOLUTION: This data distribution system is constituted by providing: a transmitting station 10 that transmits multiple stream Scd formed by multiplexing encoding streams C1 to Cn with control data D to a communication cannel as carrier waves Wcd; and a terminal station 20 that separates the encoding streams C1 to Cn and the control data D from the multiple stream Scd to be obtained by receiving the carrier waves Wcd of the communication channel and controls reception of the carrier waves Wcd in the communication channel according to the control data D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data distribution system, a transmitting station and a terminal station for distributing data from a transmitting station to a terminal station through a communication channel, and more particularly to a terminal station according to control data from the transmitting station. It relates to control of communication channels.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing the configuration of a conventional data distribution system. This data distribution system is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-187378. Figure 3
In the figure, 110 is a transmitting station and 120 is a terminal station.

In the transmitting station 110, 111-1 to 11-11
Reference numeral 1-n is an encoder unit that encodes media data such as video and audio and outputs encoded streams C1 to Cn, respectively, and 112 is control data that generates control data D for controlling a receiving operation in the terminal station 120. Generator, 11
Reference numeral 3 denotes a multiplexing unit that multiplexes the coded streams C1 to Cn and outputs one multiplexed stream Sc.

Further, in the transmitting station 110, 114 carries out a modulation process for transmitting the multiplex stream Sc to the transmission line, and a modulation signal Wc (carrier frequency Fc, transmission band Δ).
Fc), a modulator 115 performs a modulation process to transmit the control data D to the transmission line, and the modulated signal Wd
A control data modulator for outputting (carrier frequency Fd, transmission band ΔFd) 116 is a modulation signal Wc and a modulation signal W.
This is a mixing unit that frequency-multiplexes d and outputs a carrier wave Wc + Wd.

On the other hand, in the terminal station 120, 121 is a tuner section for selecting a desired communication channel from the carrier waves Wc + Wd, 122 is a demodulation section for demodulating the communication channel selected by the tuner section 121 and outputting a multiplexed stream Sc, 123. Is a separation unit that separates the desired coded streams C1 to Cn from the multiplex stream Sc, and 124 is a decoder unit that decodes the coded streams C1 to Cn separated by the separation unit 123.

In the terminal station 120, 125 is a control data demodulation section for selecting a communication channel of the control data D from the carrier waves Wc + Wd and demodulating the control data D, 126.
Is a communication channel control unit that controls the receiving operation of the terminal station 120 based on the demodulated control data D.

Next, the operation will be described. Transmitting station 110
Then, the encoder units 111-1 to 111-n encode media data such as video and audio, and output the encoded streams C1 to Cn to the multiplexing unit 113. The multiplexing unit 113 multiplexes the coded streams C1 to Cn to generate one multiplexed stream Sc, and the modulation unit 114 multiplexes the multiplexed stream S.
c is modulated to be transmitted to the transmission path, and the modulated signal Wc is output.

The control data generation unit 112 includes a terminal station 120.
Control data D for controlling the reception operation of the control data D is generated, and the control data modulator 115 modulates the control data D for transmission to the transmission path and outputs the modulation signal Wd. Modulator 11
4 and the modulated signals Wc and Wd modulated by the control data modulator 115 are frequency-multiplexed by the mixer 116, and the carrier wave W
It is transmitted to the transmission line as c + Wd.

In the terminal station 120, when the carrier wave Wc + Wd is received via the transmission line, the tuner section 121 receives the carrier wave Wc.
A desired communication channel is selected from c + Wd, and the demodulation unit 12
2, the demodulation process is performed. Further, the demodulated signal is separated by the separation unit 123 into desired encoded streams C1 to Cn from the multiplex stream Sc. Decoder section 1
Reference numeral 24 denotes the encoded streams C1 to C1 separated by the separation unit 123.
Cn is decoded and media data such as video and audio is output. In addition, the control data demodulation unit 125 uses the carrier wave Wc + W.
The communication channel of the control data D is selected from d, the control data D is demodulated, and the communication channel control unit 126 controls the receiving operation of the tuner unit 121 based on the control data D.

FIG. 4 is a diagram schematically showing the spectrum Xc of the modulation signal Wc, the spectrum Xd of the modulation signal Wd, and the spectrum Xc + Xd of the carrier wave Wc + Wd. 4A, 4B, and 4C show the spectrum Xc, the spectrum Xd, and the spectrum Xc + Xd, respectively.

As can be seen from FIG. 4C, the spectrum Xc + Xd has a transmission band ΔFd of the spectrum Xd in addition to the transmission band ΔFc of the spectrum Xc. Thus, in the conventional data distribution system, the transmitting station 11
In order to transmit the carrier wave Wc + Wd from 0 to the terminal station 120, it is necessary to allocate the transmission band ΔFd for transmitting the control data D, and the utilization efficiency of the frequency band is poor.

[0012]

Since the conventional data distribution system is configured as described above, it is necessary to allocate the frequency band for transmitting the control data, which causes a problem that the utilization efficiency of the frequency band is poor. there were.

Further, the conventional data distribution system requires a control data modulating section of the transmitting station and a control data demodulating section of the terminal station, which complicates the configuration of the transmitting station and the receiving station, and causes an extra cost. There was a problem that occurred.

The present invention has been made to solve the above problems, and is a data distribution system capable of improving the utilization efficiency of a frequency band without allocating a transmission band for transmitting control data. , Providing a transmitting station and a terminal station.

Further, according to the present invention, the control data modulating section of the transmitting station and the control data demodulating section of the terminal station are not required, the configurations of the transmitting station and the receiving station can be simplified, and unnecessary costs can be reduced. The purpose of the present invention is to provide a new data distribution system, a transmitting station, and a terminal station.

[0016]

A data distribution system according to the present invention includes an encoder section for encoding data into an encoded stream, and control data for generating control data for designating a communication channel for a terminal station. A transmission station is configured by a generation unit, a multiplexing unit that multiplexes an encoded stream and control data into one multiplexed stream, and a transmission interface unit that transmits the multiplexed stream to a communication channel, and receives the multiplexed stream from the communication channel. A receiving interface section, a separating section for separating the encoded stream and the control data from the multiplexed stream received by the receiving interface section, a decoder section for decoding the data from the encoded stream separated by the separating section, and a separating section. Causes the reception interface unit to receive the communication channel according to the control data Terminal station and a signal channel control unit is that so as to be configured.

In the data distribution system according to the present invention, in the transmitting station, the control data generating unit generates the control data according to the carrier frequency and the transmission band of the communication channel or the indexes respectively assigned to the communication channels. Is.

In the data distribution system according to the present invention, in the transmitting station, the control data generating unit generates time data for designating the reception change time of the communication channel for the terminal station, and the terminal data is generated. In the above, the communication channel control unit causes the reception interface unit to receive the communication channel specified by the control data at the reception change time specified by the time data.

In the data distribution system according to the present invention, in the transmitting station, the control data generating unit generates a plurality of sets of time data for designating the reception change time of the communication channel to the terminal station, In the terminal station, the communication channel control unit causes the reception interface unit to sequentially receive the communication channel specified by the control data at each reception change time specified by the time data.

In the data distribution system according to the present invention, in the transmitting station, the control data generating unit generates the ID data for designating the ID of the terminal station, and in the terminal station, the ID data is generated by the terminal station itself. When the ID is designated, the communication channel control unit causes the reception interface unit to receive the communication channel designated by the control data.

In the data distribution system according to the present invention, the transmitting station transmits the restoration control data for designating the restoration communication channel to the terminal station to the default communication channel, and the terminal station synchronizes the restoration control data. If it falls into a state that cannot be obtained, the communication channel control unit causes the reception interface unit to receive the recovery control data, and the communication channel control unit receives the communication channel indicated by the recovery control data by the reception interface unit. It was made to let.

In the data distribution system according to the present invention, in the terminal station, the communication channel control unit causes the reception interface unit to receive the default communication channel when the unsynchronized state continues beyond the time threshold. It is a thing.

In the data distribution system according to the present invention, the transmitting station transmits the restoration control data for designating the restoration communication channel to the terminal station to the default communication channel, and the default to the terminal station. If the control data generation unit generates the default designation data for designating the communication channel or the index assigned to the default communication channel in the control data, and the terminal station falls into a state where synchronization is not possible, the default designation data The communication channel control unit causes the reception interface unit to receive the specified default communication channel or the default communication channel to which the index is assigned, and acquires the recovery control data, and the communication channel control unit determines the communication channel indicated by the recovery control data. Make the receiving interface part receive Those were.

In the data distribution system according to the present invention, in the transmitting station, the control data generating unit generates the time threshold value or the index assigned to the time threshold value by including it in the default designation data, and in the terminal station, the time threshold value or the index is generated. The communication channel control unit causes the reception interface unit to receive the default communication channel when the state of being out of synchronization continues beyond the assigned time threshold.

A transmitting station according to the present invention transmits a multiplexed stream in which an encoded stream and control data are multiplexed to a communication channel, and at the same time receives the encoded stream and control data from the multiplexed stream obtained by receiving the communication channel. The terminal station is separated, and the terminal station is controlled to receive the communication channel according to the control data.

In the terminal station according to the present invention, when the multiplexed stream obtained by multiplexing the coded stream and the control data is transmitted from the transmitting station to the communication channel, the multiplexed stream obtained by receiving the communication channel is changed to the encoded stream. The control data is separated and the reception of the communication channel is controlled according to the control data.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a diagram showing a configuration of a data distribution system according to a first embodiment of the present invention. In FIG. 1, 10 is a transmitting station and 20 is a terminal station.

In the transmitting station 10, 11-1 to 11-n
Is an encoder unit that encodes media data such as video and audio and outputs encoded streams C1 to Cn, and 12 is a control data generation unit that generates control data D for controlling a communication channel received by the terminal station 20. 1
Reference numeral 3 denotes a multiplexing unit that multiplexes the coded streams C1 to Cn and the control data D and outputs one multiplexed stream Scd.
Reference numeral 14 denotes a carrier wave Wcd (carrier wave frequency Fc for performing modulation processing for transmitting the multiplexed stream Scd to the transmission path.
d, a transmission band ΔFcd).

Further, in the terminal station 20, 21 is a reception interface section for selecting a desired communication channel from the carrier wave Wcd and outputting the multiplex stream Scd, and 22 is a desired encoded stream C1 to C from the multiplex stream Scd.
n is a separation unit that separates the control data D, and 23 is a separation unit 2
A decoder unit that decodes the encoded streams C1 to Cn separated by 2 and a communication channel control unit 24 that controls the communication channel of the reception interface unit 21 according to the control data D separated by the separation unit 22.

Next, the operation will be described. In the transmitting station 10, the encoder units 11-1 to 11-n encode media data such as video and audio, and output the encoded streams C1 to Cn to the multiplexing unit 13, respectively. The control data generation unit 12 also generates control data D for controlling the communication channel of the terminal station 20. Here, the carrier wave Wc
It is assumed that the carrier frequency Fcd of d and the transmission band ΔFcd are notified to the terminal station 20 by the control data D. The multiplexing unit 13 multiplexes the coded streams C1 to Cn and the control data D to generate one multiplexed stream Scd, and the transmission interface unit 14 modulates the multiplexed stream Scd for transmitting to the transmission path, and the carrier wave Wcd. To the transmission line.

At the terminal station 20, the carrier wave W is transmitted via the transmission line.
Upon receiving cd, the reception interface unit 21 selects a desired communication channel from the carrier wave Wcd, further demodulates it, and outputs the multiplexed stream Scd. The separation unit 22 separates the desired encoded streams C1 to Cn and the control data D from the multiple stream Scd. The decoder unit 23 includes the encoded streams C1 to C separated by the separation unit 22.
It decodes n and outputs media data such as video and audio.

The communication channel control section 24 controls the communication channel of the reception interface section 21 based on the control data D separated by the separation section 22. That is, the communication channel control unit 24 determines the carrier frequency Fc of the carrier Wcd.
d, the transmission band ΔFcd is recognized from the control data D, and the communication channel of the reception interface unit 21 is adjusted.

FIG. 2 is a diagram schematically showing the spectrum Xcd of the carrier wave Wcd. In the first embodiment, in the transmitting station 10, the coded streams C1 to Cn and the control data D are collectively multiplexed by the multiplexing unit 13 and multiplexed stream Sc.
Since the transmission interface unit 14 generates the carrier wave Wcd from the multiplex stream Scd by generating d, the spectrum Xcd does not require a transmission band for transmitting the control data D, as shown in FIG. ing. Therefore, compared to the conventional data distribution system, the frequency band can be used more efficiently.

In addition to the configuration of the transmitting station 10 described above,
In the terminal station 20, the reception interface unit 21 uses the carrier wave W.
Since the multiplexed stream Scd is demodulated from cd and the encoded streams C1 to Cn and the control data D are separated by the separation unit 22, the control data modulation unit and the control data demodulation unit are not required. Therefore, compared to the conventional data distribution system, the configurations of the transmitting station 10 and the terminal station 20 can be simplified, and unnecessary costs can be reduced.

The receiving channel control of the terminal station 20 by the control data D is performed by the carrier frequency Fc of the carrier wave Wcd.
d, the control of the communication channel is not limited to the notification of the transmission band ΔFcd.

Further, the carrier frequency F as a concrete numerical value
Instead of notifying the cd and the transmission band ΔFcd to the terminal station 20 by the control data D, it may be notified by using a certain discrete numerical value (index).

For example, in a satellite communication system, the usable frequency band is divided into transponder units (for example, 36M).
Hz band), the transponder is further divided into certain slots (transponders are divided by the transmission band of the carrier), and the transponder, the transmission bandwidth, and the slot are pre-assigned and used.

Similar to this example, each communication channel (or carrier frequency Fcd, used in the data distribution system,
A different index is previously assigned to the transmission band ΔFcd, and the control data generation unit 12 generates this index as the control data D, and the index of the received control data D is assigned to the communication channel (or carrier frequency Fcd, transmission band). [Delta] Fcd) so that the reception interface unit 21 is connected to the communication channel control unit 2
4 controls. By doing so, the effect that the data amount of the control data D transmitted from the transmitting station 10 can be reduced can be obtained.

Further, the data to be distributed is not limited to media data such as video and audio, but other data may be distributed. In addition, the transmitting station 10 and the terminal station 2
The number of 0s and the number of communication channels are not particularly limited.

As described above, according to the first embodiment, the encoder sections 11-1 to 11-11 for encoding media data such as video and audio into the encoded streams C1 to Cn.
-N, a control data generation unit 12 that generates control data D for designating a communication channel for the terminal station 20,
A multiplexing unit 13 that multiplexes the encoded stream and the control data D into one multiplexed stream Scd, and the multiplexed stream S.
The transmitting station 10 is composed of the transmission interface unit 14 that transmits cd to the communication channel as the carrier wave Wcd, and the receiving interface unit 21 that receives the multiple stream Scd from the carrier wave Wcd of the communication channel and the multiple stream received by the receiving interface unit 21. A separation unit 22 that separates the encoded stream and the control data D from Scd;
A decoder unit 23 for decoding data from the encoded stream separated by the separation unit 22; and a communication channel control unit 24 for causing the reception interface unit 21 to receive the carrier wave Wcd of the communication channel according to the control data D separated by the separation unit 22. Since the terminal station 20 is configured from
The effect that the transmission band for transmitting the control data D is unnecessary and the utilization efficiency of the frequency band can be improved is obtained. In addition, a configuration for modulating / demodulating the control data D is provided in the transmitting station 10 or the terminal station. Since it is not necessary to provide the transmitter 20 and the terminal station 20, the configurations of the transmission station 10 and the terminal station 20 can be simplified and the cost can be reduced.

Further, according to the first embodiment, in the transmitting station 10, the control data generating section 12 is adapted to generate the control data D by the carrier frequency Fcd of the communication channel and the transmission band ΔFcd. Due to
The effect that the communication channel can be surely received in the terminal station 20 is obtained.

Further, according to the first embodiment, in the transmitting station 10, the control data generating unit 12 generates the control data D by the indexes respectively assigned to the different communication channels. The data amount of the control data D transmitted from the terminal station 2 is reduced.
The effect that the communication channel at 0 can be reliably received is obtained.

Embodiment 2. The control data D described in the first embodiment may include the time data T so that the terminal station 20 receives the communication channel indicated by the control data D at the time indicated by the time data T. Hereinafter, this method will be described. The data delivery system according to the second embodiment has the same configuration as that of the first embodiment (FIG. 1), and therefore the illustration thereof is omitted.

Next, the operation will be described. In the transmitting station 10, the encoder units 11-1 to 11-n encode media data such as video and audio, and output the encoded streams C1 to Cn to the multiplexing unit 13, respectively. Further, the control data generation unit 12 generates control data D for controlling the communication channel of the terminal station 20, and also generates time data T for designating the change time of the communication channel to the terminal station 20, and the control data D And outputs the time data T to the multiplexer 13. The multiplexing unit 13 multiplexes the coded streams C1 to Cn and the control data D into one multiplexed stream Scd.
And the transmission interface unit 14 modulates the multiplexed stream Scd to transmit it to the transmission path, and the carrier wave Wcd is generated.
To the transmission line.

In the terminal station 20, the carrier wave W is transmitted via the transmission line.
Upon receiving cd, the reception interface unit 21 selects a desired communication channel from the carrier wave Wcd, further demodulates it, and outputs the multiplexed stream Scd. The separation unit 22 separates the desired encoded streams C1 to Cn and the control data D from the multiple stream Scd. The decoder unit 23 includes the encoded streams C1 to C separated by the separation unit 22.
It decodes n and outputs media data such as video and audio.

Further, the communication channel control section 24 controls the communication channel of the reception interface section 21 based on the control data D separated by the separation section 22. That is, the communication channel control unit 24 determines the carrier frequency Fc of the carrier Wcd.
d, the transmission band ΔFcd is recognized from the control data D, and the reception interface unit 21 is controlled to change the reception to the communication channel of the carrier frequency Fcd and the transmission band ΔFcd at the time designated by the time data T.

In this way, the time data T is added to the control data D.
By controlling the communication channel in the terminal station 20 and the reception change time thereof in the transmitting station 10, the communication on the side of the terminal station 20 is performed especially when the data distribution system is operated using a plurality of carrier waves Wcd. Channel control (when,
Which channel is to be viewed) can be performed on the transmitting station 10 side, and fine data distribution can be performed.

In the above description, the reception change time of the communication channel at the terminal station 20 is specified by the time data T, but the following two methods may be used and the same effect can be obtained.

The reception change of the communication channel at the terminal station 20 is immediately executed by the time data T. This is, for example, a time that cannot actually be used as the time data T (25:00, etc.)
When the time data T is received, the terminal station 20 immediately switches the reception to the communication channel designated by the control data D.

A plurality of sets of two data pairs of the communication channel (control data D) and the reception change time (time data T) of the communication channel are transmitted, and the terminal station 20 side sets a plurality of sets of communication channels and communication channels. The communication channels are sequentially changed according to the reception change time.

As described above, according to the second embodiment, in the transmitting station 10, the control data generator 12 controls the time data T for designating the reception change time of the communication channel to the terminal station 20. Since the data is generated by including it in the data D, the communication channel control unit 24 causes the reception interface unit 21 to receive the communication channel specified by the control data D at the reception change time specified by the time data T in the terminal station 20. The effect of being able to perform fine data distribution is obtained.

Further, according to the second embodiment, in the transmitting station 10, the control data generating unit 12 converts the time data T for designating the immediate reception channel change to the terminal station 20 into the control data D. The terminal station 20 generates
When the time data T is received, the communication channel control unit 24 causes the reception interface unit 21 to receive the communication channel designated by the control data D, so that an effect that fine data distribution can be performed is obtained.

Further, according to the second embodiment, in the transmitting station 10, the control data generating unit 12 converts the time data T for designating the reception change time of the communication channel to the terminal station 20 into the control data D. Generate multiple sets including the terminal station 2
In the case of 0, the communication channel control unit 24 causes the reception interface unit 21 to sequentially receive the communication channels specified by the control data D at each reception change time specified by the time data T, so that fine data distribution should be performed. The effect of being able to do is obtained.

Embodiment 3. ID designation of the terminal station 20 for which the control data D is valid (the terminal is identified by the ID)
The ID data I to be controlled may be included in the control data D. Hereinafter, this method will be described. The data distribution system according to the third embodiment is the same as that of the first embodiment.
Since the configuration is the same as that of FIG. 1, the illustration is omitted.

Next, the operation will be described. In the transmitting station 10, the encoder units 11-1 to 11-n encode media data such as video and audio, and output encoded streams C1 to Cn, respectively. In addition, the control data generation unit 12
Generates the control data D for controlling the communication operation of the terminal station 20, the ID data I designating the ID of the terminal station 20 for which the control data D is valid, and the ID data I in the control data D. It outputs to the multiplexing part 13 including. The multiplexing unit 13 controls the encoded streams C1 to Cn and the control data D.
Are multiplexed to generate one multiplexed stream Scd, and the transmission interface unit 14 modulates the multiplexed stream Scd for transmission to the transmission line and outputs the carrier wave Wcd to the transmission line.

At the terminal station 20, the carrier wave W is transmitted via the transmission line.
Upon receiving cd, the reception interface unit 21 selects a desired communication channel from the carrier wave Wcd and further demodulates it to generate a multiplex stream Scd. The separation unit 22 separates the desired encoded streams C1 to Cn and the control data D from the multiple stream Scd. The decoder unit 23 includes the encoded streams C1 to C separated by the separation unit 22.
It decodes n and outputs media data such as video and audio.

The communication channel control section 24 controls the communication channel of the reception interface section 21 based on the control data D separated by the separation section 22. That is, if the ID data I in the control data D specifies the terminal station 20 itself as an ID, the communication channel control unit 24 uses the carrier wave W.
The carrier frequency Fcd and the transmission band ΔFcd of cd are recognized from the control data D, and the carrier frequency Fcd and the transmission band ΔF are recognized.
The reception interface unit 21 is controlled so as to change reception to the cd communication channel.

By using the ID data I, it becomes possible to set different control data Di (i is the ID number of the terminal station 20) for each terminal station 20, and like the case of the time data T, the terminal station 20 can be set. You can finely control the communication channel of. Further, it becomes possible to exclude the reception of the terminal station 20 which has not acquired the ID due to the non-contract.

As described above, according to the third embodiment, in the transmitting station 10, the control data generating unit 12 generates the ID data I for designating the ID of the terminal station 20 by including it in the control data D, In the terminal station 20, when the ID data I specifies the terminal station 20 itself, the communication channel control unit 24 causes the reception interface unit 21 to receive the communication channel specified by the control data D.
The effect that the communication channel of 0 can be finely controlled is obtained, and the terminal station 2 which has not acquired the ID due to the non-contract
The effect that the reception of 0 can be eliminated is obtained.

Fourth Embodiment When data distribution ends,
The carrier wave Wcd is disconnected and the terminal station 20 is out of synchronization. In addition to this, even if the carrier wave Wcd is momentarily cut off or the required reception level is lowered due to an external factor such as an obstacle or the weather, the terminal station 20 becomes out of synchronization. In the fourth embodiment, a method of recovering the synchronization from the disconnected state due to the end of data distribution will be described.
The data distribution system according to the fourth embodiment is
Since the configuration is the same as that of the first embodiment (FIG. 1), its illustration is omitted.

Next, the operation will be described. In the transmitting station 10, the encoder units 11-1 to 11-n encode media data such as video and audio, and output the encoded streams C1 to Cn to the multiplexing unit 13, respectively. The control data generation unit 12 also generates control data D for controlling the communication channel of the terminal station 20. Here, the carrier wave Wc
It is assumed that the carrier frequency Fcd of d and the transmission band ΔFcd are notified to the terminal station 20 by the control data D. The multiplexing unit 13 multiplexes the coded streams C1 to Cn and the control data D to generate one multiplexed stream Scd, and the transmission interface unit 14 modulates the multiplexed stream Scd for transmitting to the transmission path, and the carrier wave Wcd. To the transmission line.

In the terminal station 20, the carrier wave W is transmitted via the transmission line.
Upon receiving cd, the reception interface unit 21 selects a desired communication channel from the carrier wave Wcd, further demodulates it, and outputs the multiplexed stream Scd. The separation unit 22 separates the desired encoded streams C1 to Cn and the control data D from the multiple stream Scd. The decoder unit 23 includes the encoded streams C1 to C separated by the separation unit 22.
It decodes n and outputs media data such as video and audio.

The communication channel control unit 24 controls the communication channel of the reception interface unit 21 based on the control data D separated by the separation unit 22. That is, the communication channel control unit 24 determines the carrier frequency Fc of the carrier Wcd.
d, the transmission band ΔFcd is recognized from the control data D, and the communication channel of the reception interface unit 21 is adjusted.

Then, when the state of being out of synchronization due to the end of data distribution or an external factor, the communication channel control unit 24 of the terminal station 20 shifts from the communication channel in the disconnected state to the default communication channel of the reception interface unit 21. Change the reception. In the fourth embodiment, the carrier frequency and the transmission band of the default communication channel are preset, and the restoration control data D ′ for restoring the communication channel is transmitted from the transmitting station 10 using the default communication channel. ing.

In the terminal station 20 in which the reception of the reception interface unit 21 is changed to the default communication channel, the communication channel control unit 24 includes the reception interface unit 21 and the separation unit 2.
The communication channel control unit 24 receives the recovery control data D ′ via the communication control unit 2 and recovers the communication channel according to the recovery control data D ′.
Control 1 By doing so, the terminal station 20 can be restored to a normal communication channel even if it falls into a state of being out of synchronization, and data transmission from the transmitting station 10 can be surely performed. Become.

Incidentally, unlike the case where the data distribution ends,
In some cases, a state in which synchronization is lost due to an external factor is a momentary disconnection (instantaneous disconnection), and this instantaneous disconnection is directly resolved, so changing the communication channel causes confusion in data delivery. In order to distinguish this momentary interruption from the interruption state that continues for a certain period of time, a time threshold value for determining the interruption state is set in advance in the communication channel control unit 24 of the terminal station 20, and the interruption state exceeds the time threshold value. When continuing, the reception may be switched to the default communication channel.

As described above, according to the fourth embodiment, the transmitting station 10 transmits the restoration control data D'for designating the restoration communication channel to the terminal station 20 to the default communication channel. At the same time, when the terminal station 20 falls into a non-synchronized state, the communication channel control unit 24 causes the reception interface unit 21 to receive the default communication channel to acquire the recovery control data D ′, and the recovery control data D. Since the communication channel control unit 24 causes the reception interface unit 21 to receive the communication channel indicated by ', even if the carrier wave becomes unsynchronized due to the end of data distribution, there is an effect that the communication channel can be normally transferred. can get.

Further, according to the fourth embodiment, in the terminal station 20, when the unsynchronized state continues beyond the time threshold, the communication channel control unit 24 sets the default communication channel to the reception interface unit 21. Since it was made to receive, the state of carrier wave disconnection due to the end of data distribution,
It is possible to distinguish the instantaneous state of the carrier wave interruption due to an external factor and prevent the confusion of data distribution.

Embodiment 5. In the fifth embodiment, based on the fourth embodiment, a method of notifying the time threshold for identifying the default communication channel and the disconnected state by the control data D will be described. The data delivery system according to the fifth embodiment has the same configuration as that of the first embodiment (FIG. 1), and therefore the illustration thereof is omitted.

Next, the operation will be described. In the transmitting station 10, the encoder units 11-1 to 11-n encode media data such as video and audio, and output the encoded streams C1 to Cn to the multiplexing unit 13, respectively. Further, the control data generation unit 12 generates control data D for designating the communication channel of the terminal station 20, and at the same time, the fourth embodiment
The default designating data Z designating the default communication channel is generated, and the control data D including the default designating data Z is output to the multiplexing unit 13. The multiplexing unit 13 multiplexes the coded streams C1 to Cn and the control data D to generate one multiplexed stream Scd, and the transmission interface unit 14 modulates the multiplexed stream Scd for transmitting to the transmission path, and the carrier wave Wcd. To the transmission line.

In the terminal station 20, the carrier wave W is transmitted via the transmission line.
Upon receiving cd, the reception interface unit 21 selects a desired communication channel from the carrier wave Wcd, further demodulates it, and outputs the multiplexed stream Scd. The separation unit 22 separates the desired encoded streams C1 to Cn and the control data D from the multiple stream Scd. The decoder unit 23 includes the encoded streams C1 to C separated by the separation unit 22.
It decodes n and outputs media data such as video and audio.

The communication channel control section 24 controls the communication channel of the reception interface section 21 based on the control data D separated by the separation section 22. That is, the communication channel control unit 24 determines the carrier frequency Fc of the carrier Wcd.
d, The transmission standby ΔFcd is recognized from the control data D, and the communication channel of the reception interface unit 21 is adjusted.

Then, when the data delivery ends or an external factor causes a loss of synchronization, the communication channel control unit 24 of the terminal station 20 disconnects to the default communication channel designated by the default designated data Z in the control data D. The reception of the reception interface unit 21 is changed from the communication channel in the state. Thereafter, as in the fourth embodiment, the recovery control data D ′ is received on the default communication channel to recover the communication channel.

By thus designating the default communication channel by the default designating data Z, it is possible to flexibly deal with the case where the default communication channel needs to be changed due to an uncertain factor such as an external factor. As a result, data distribution can be surely performed.

The time threshold value for identifying the disconnection state described in the fourth embodiment may be included in the default designation data Z. Even in this case, the same effect can be obtained.

Furthermore, the default designation data Z may be generated using the index described at the end of the first embodiment. That is, the default communication channel,
The data amount of the default designated data Z can be reduced by designating the time threshold value by the index.

As described above, according to the fifth embodiment, the transmitting station 10 transmits the restoration control data D'for designating the restoration communication channel to the terminal station 20 to the default communication channel. In addition, when the control data generation unit 12 generates the default designation data Z for designating the default communication channel for the terminal station 20 by including it in the control data D, the terminal station 20 falls into a state where synchronization cannot be achieved. , The communication channel control unit 24 causes the reception interface unit 21 to receive the default communication channel designated by the default designation data Z to obtain the restoration control data D ′, and the communication channel control is performed on the communication channel indicated by the restoration control data D ′. Since the unit 24 causes the reception interface unit 21 to receive the data, it is possible to avoid the confusion of the data distribution system. Is also flexibility to accommodate changes in the default communications channel, the effect is obtained that the data delivery can be reliably performed.

Further, according to the fifth embodiment, in the transmitting station 10, the control data generating unit 12 generates the time threshold value by including it in the default designation data Z, and in the terminal station 20, synchronization is performed after exceeding the time threshold value. When the state that cannot be taken is continued, the communication channel control unit 24 causes the reception interface unit 21 to receive the default communication channel. Therefore, the state of carrier interruption due to the end of data distribution and the state of instantaneous carrier interruption due to external factors. Can be identified, the default communication channel can be flexibly dealt with, and data can be delivered reliably.

Further, according to the fifth embodiment, in the transmitting station 10, the control data generating unit 12 generates the default designation data Z by the index assigned to the default communication channel, and the terminal station 20 is synchronized. When it falls into a state where there is no index, the communication channel control unit 24 causes the reception interface unit 21 to receive the default communication channel to which the index is assigned, so that the data amount of the default designation data Z can be reduced.

Further, according to the fifth embodiment, in the transmitting station 10, the control data generating unit 12 generates the default designation data Z by the index assigned to the time threshold, and in the terminal station 20, the index is assigned. When the state of being out of synchronization continues beyond the predetermined time threshold, the communication channel control unit 24 causes the reception interface unit 2 to
Since 1 is made to receive the default communication channel, the data amount of the default designation data Z can be reduced.

[0081]

As described above, according to the present invention, an encoder section for encoding data into an encoded stream and a control data generating section for generating control data for designating a communication channel for a terminal station. And a receiving unit for receiving the multiplex stream from the communication channel, the transmitting station being composed of a multiplex section for multiplexing the encoded stream and the control data into one multiplex stream and a transmission interface section for transmitting the multiplex stream to the communication channel. Interface part,
According to the control data separated by the separation unit separating the encoded stream and the control data from the multiplex stream received by the reception interface unit, the decoder unit decoding the data from the encoded stream separated by the separation unit, and the separation unit, Since the terminal station is configured by the communication channel control unit that causes the reception interface unit to receive the communication channel, the effect that the transmission band for transmitting the control data is unnecessary and the frequency band utilization efficiency can be improved In addition, there is no need to provide a configuration for modulating / demodulating control data in a transmitting station or a terminal station.
The effect that the configuration of the terminal station can be simplified and the cost can be reduced is obtained.

According to the present invention, in the transmitting station, the control data generating section generates the control data according to the carrier frequency and the transmission band of the communication channel or the indexes respectively assigned to the communication channels. The effect that the reception of the communication channel can be surely performed is obtained, and when the index is used, the amount of data to be transmitted can be reduced.

According to the present invention, in the transmitting station, the control data generating unit generates time data for designating the reception change time of the communication channel to the terminal station, and the terminal data generates the time data. Since the communication channel control unit causes the reception interface unit to receive the communication channel specified by the control data at the reception change time specified by the data, it is possible to obtain the effect that fine data distribution can be performed.

According to the present invention, in the transmitting station, the control data generating unit generates a plurality of sets of time data for designating the reception change time of the communication channel to the terminal station. Since the communication channel control unit causes the reception interface unit to sequentially receive the communication channel specified by the control data for each reception change time specified by the time data, it is possible to obtain the effect that fine data distribution can be performed. To be

According to the present invention, in the transmitting station, the control data generating unit generates the ID data for designating the ID of the terminal station by including it in the control data, and in the terminal station, the ID data designates the terminal station itself. In this case, the communication channel control unit causes the reception interface unit to receive the communication channel designated by the control data, so that the communication channel of the terminal station can be finely controlled, and the ID can be obtained without a contract. The effect that the reception of the terminal station which is not performing can be eliminated is obtained.

According to the present invention, the transmitting station transmits the restoration control data for designating the restoration communication channel to the terminal station to the default communication channel, and the terminal station is in a state where synchronization cannot be established. In this case, the communication channel control unit causes the reception interface unit to receive the default communication channel to acquire the recovery control data, and the communication channel control unit causes the reception interface unit to receive the communication channel indicated by the recovery control data. Because I did
Even if the carrier wave becomes unsynchronized due to the end of the data distribution, the effect of being able to normally shift to the communication channel can be obtained.

According to the present invention, in the terminal station, when the unsynchronized state continues beyond the time threshold, the communication channel control unit causes the reception interface unit to receive the default communication channel. The disconnection state of the carrier due to the end of distribution and the instantaneous disconnection state of the carrier due to an external factor can be identified, and the effect of preventing confusion in data distribution can be obtained.

According to the present invention, the transmitting station transmits the restoration control data for designating the restoration communication channel to the terminal station and transmits the restoration communication data to the terminal station. If the control data generation unit generates the default specified data for specifying or the index assigned to the default communication channel in the control data and the terminal station falls into a state where synchronization is not possible, the default specified by the default specified data The communication channel control unit causes the reception interface unit to receive the communication channel or the default communication channel to which the index is assigned to obtain the recovery control data, and the communication channel control unit receives the communication channel indicated by the recovery control data from the reception interface unit. Since it was made to receive it, Effect is obtained of avoiding the confusion of the system, also can flexibly respond to changes in the default communications channel, the effect is obtained that the data delivery can be reliably performed, when using the index,
The effect is that the amount of data to be transmitted can be reduced.

According to the present invention, in the transmitting station, the control data generating unit generates the time threshold value or the index assigned to the time threshold value by including it in the default designation data, and in the terminal station, the time threshold value or the index is assigned. The communication channel control unit has the receiving interface unit receive the default communication channel when the synchronization continues beyond the specified time threshold. The effect of being able to identify the instantaneous state of carrier wave interruption due to, being able to flexibly respond to changes in the default communication channel, and ensuring reliable data distribution. When an index is used, the amount of data sent The effect of being able to reduce

According to the present invention, the multiplexed stream obtained by multiplexing the encoded stream and the control data is transmitted to the communication channel, and the encoded stream and the control data are transmitted from the multiplexed stream obtained by receiving the communication channel to the terminal station. Since the terminal station controls the reception of the communication channel according to the control data, the transmission band for transmitting the control data becomes unnecessary, and the effect of improving the frequency band utilization efficiency can be obtained. ,in addition,
There is no need to provide a configuration for modulating / demodulating control data in the transmitting station or the terminal station, and the configuration of the transmitting station or the terminal station can be simplified and the cost can be reduced.

According to the present invention, when the multiplexed stream obtained by multiplexing the encoded stream and the control data is transmitted from the transmitting station to the communication channel, the encoded stream and the control data are obtained from the multiplexed stream obtained by receiving the communication channel. Since it is separated from each other and the reception of the communication channel is controlled according to the control data, the effect that the transmission band for transmitting the control data is unnecessary and the frequency band utilization efficiency can be improved, is obtained. In addition, it is not necessary to provide a configuration for modulating / demodulating control data in the transmitting station or the terminal station, and the configurations of the transmitting station and the terminal station can be simplified and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a data distribution system according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically showing a spectrum Xcd of a carrier wave Wcd.

FIG. 3 is a diagram showing a configuration of a conventional data distribution system.

FIG. 4 is a spectrum Xc of a modulation signal Wc and a modulation signal W.
spectrum Xd of d, spectrum X of carrier Wc + Wd
It is a figure which respectively shows c + Xd typically.

[Explanation of symbols]

10 transmitting station, 11-1 to 11-n encoder unit, 1
2 control data generation unit, 13 multiplexing unit, 14 transmission interface unit, 20 terminal station, 21 reception interface unit, 22 separation unit, 23 decoder unit, 24 communication channel control unit, C1 to Cn encoded stream, D control data, Fcd Carrier frequency, Scd multiple stream, Wcd carrier, Xcd spectrum, ΔFcd
Transmission band.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Daisuke Tsukahara             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Yasutaka Akita             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F term (reference) 5K028 AA11 KK01 KK03 MM08 MM12                       TT02

Claims (11)

[Claims] 1. A data distribution system in which data is distributed from a transmitting station to a terminal station via a communication channel, wherein the transmitting station includes an encoder section for encoding the data into an encoded stream, and the terminal station for the terminal station. A control data generation section for generating control data for designating the communication channel, a multiplexing section for multiplexing the encoded stream and the control data into one multiplexed stream, and the multiplexed stream for the communication channel. The terminal station comprises a reception interface section for receiving the multiplex stream from the communication channel, and the encoded stream and the control data from the multiplex stream received by the reception interface section. From the separation unit to be separated and the encoded stream separated by the separation unit, Data distribution system for a decoder which decodes over data, according to the control data separated by the separating unit, characterized in that it is a communication channel control unit and for receiving the communication channel to the receiving interface unit. 2. The data according to claim 1, wherein in the transmitting station, the control data generating unit generates the control data according to the carrier frequency and the transmission band of the communication channel or the indexes respectively assigned to the communication channels. Delivery system. 3. In the transmitting station, the control data generating unit generates time data for designating the reception change time of the communication channel to the terminal station, and the control data generating unit generates the time data. 2. The data distribution system according to claim 1, wherein the communication channel control unit causes the reception interface unit to receive the communication channel specified by the control data at the specified reception change time. 4. In the transmitting station, the control data generating unit generates a plurality of sets of time data for designating the reception change time of the communication channel to the terminal station, and the control data generating unit generates a plurality of sets. The data distribution system according to claim 1, wherein the communication channel control unit causes the reception interface unit to sequentially receive the communication channel specified by the control data at each reception change time specified by the data. 5. In the transmitting station, the control data generating unit generates ID data for designating the ID of the terminal station by including it in the control data, and in the terminal station, the ID data designates the terminal station itself. In this case, the communication channel control unit causes the reception interface unit to receive the communication channel designated by the control data. 6. The transmitting station transmits recovery control data for designating a communication channel for recovery to the terminal station to the default communication channel, and when the terminal station falls into a state where synchronization cannot be achieved. , The communication interface controller receives the default communication channel to acquire the recovery control data, and the communication channel controller causes the reception interface unit to receive the communication channel indicated by the recovery control data. The data distribution system according to claim 1, wherein: 7. The terminal station according to claim 6, wherein the communication channel control unit causes the reception interface unit to receive the default communication channel when the unsynchronized state continues beyond the time threshold value. Data distribution system. 8. The transmitting station transmits restoration control data for designating a restoration communication channel to the terminal station to the default communication channel, and designates the default communication channel to the terminal station. If the control data generation unit generates the default specified data for the above or the index assigned to the above default communication channel in the control data, and the terminal station becomes out of synchronization, the above specified default data is specified. The communication channel control unit causes the receiving interface unit to receive the default communication channel or the default communication channel to which the index has been assigned, to obtain the recovery control data, and communicate the communication channel indicated by the recovery control data. The channel control unit receives the reception interface unit. The data delivery system according to claim 1, wherein the data delivery system is provided. 9. In the transmitting station, the control data generating unit generates by including the time threshold value or the index assigned to the time threshold value in the default designation data, and in the terminal station, the time threshold value or the index is assigned. 9. The data distribution system according to claim 8, wherein the communication channel control unit causes the reception interface unit to receive the default communication channel when the unsynchronized state continues beyond the time threshold. 10. A terminal station that transmits a multiplexed stream obtained by multiplexing an encoded stream and control data to a communication channel, and at the same time receives the encoded stream and the control data from the multiplexed stream obtained by receiving the communication channel. And transmitting the communication channel to the terminal station in accordance with the control data. 11. When a multiplexed stream obtained by multiplexing an encoded stream and control data is transmitted from a transmitting station to a communication channel, the encoded stream and the control data are obtained from the multiplexed stream obtained by receiving the communication channel. And a terminal station for controlling reception of the communication channel according to the control data.