JPH0783319B2 - Television signal satellite communication system - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to television systems, and in particular to remote switching of television systems.

(Prior Art) With the adoption of satellite relay of television signals, the technology has been dramatically developed by increasing the opportunity to provide a variety of news, entertainment, education and sports programs to viewers. Conceptually, the realization of these diverse possibilities requires a large number of means, such as precise switching means between the various programs and / or a device for controlling local equipment at the location of reception of radio waves from the satellite. .

(PROBLEMS TO BE SOLVED BY THE INVENTION) A 24-hour satellite news network consists of national, regional and local news sources, as well as regional and local commercials for each time slot within a given program time. Is a form of such a satellite communication system that is assigned to each terminal. In this system, appropriate switching and device control capabilities are required for terminal stations of individual local cable television systems, and in addition to news production and satellite broadcasting, It is necessary to properly coordinate the various tasks.

An object of the present invention is to provide a structure for utilizing the capabilities of a television system more than ever before.

Therefore, the present invention broadly defines a central uplink facility for transmitting to a satellite a primary video signal of a primary video program in which data including address and command information is inserted in a non-video portion, and a plurality of local subscriber receptions. A device, a plurality of regional uplink stations each transmitting a different video program to a satellite, and receiving the primary video signal and the different video program and transmitting this to a local subscriber receiving device, In a satellite communication system comprising a satellite having a plurality of transponders for transmitting the primary video signal to the regional uplink station, each local subscriber receiving device provides at least a video program not via the satellite. By separating the data from one source and from the primary video signal, this data and Comprising a motor vent primary video signal and the respective video decoder device supplied as a separate data output signal and the primary video output signal, a plurality of video program input and one of the video program output,
One of the video program inputs is the primary video program from the video decoder device and the other one of the video program inputs is the other video program.
Also, a video switching device in which a video program not transmitted via a satellite is coupled to another one of the video program inputs, and data having a specific address and including the same address from the video decoder device. The video switching device video provided to the subscriber of the local subscriber receiving device by sending a control signal to the video switching device in response to the output signal.
A computer device for selecting one of the video program inputs as a program output according to instruction information contained in the data output signal, each regional uplink station by separating the data from a primary video signal. A video decoder device which supplies this data as a data output signal, and the different video programs according to the instruction information included in the data output signal having a specific address and including the same address from the video decoder device. A computer device operative to be transmitted to the satellite, the primary video from the central uplink facility at each local subscriber receiving device.
Switching between programs, separate video programs from multiple regional uplink stations, and non-satellite video programs are all controlled based on command information contained in the primary video signal from the central uplink facility. It is intended to provide a satellite communication system characterized by the following.

Here, the data contained in the primary video signal from the central uplink facility, which is inserted in the vertical blanking interval, is transmitted via satellite to multiple individual local cable
A technique for realizing a switching method for transmitting to a television device will be described with reference to the accompanying drawings.

For example, in a satellite communications news network receiving signals from two transponders, one for national news and one for local news, where each local cable unit is located on the same satellite, the primary national news signal from the central uplink. Is deciphered by the decoder / sync / switching equipment on the cable equipment side, national news, regional news, and local news produced by the cable system, video tape playback, and other special news by transponders.・
It contains coded data that controls switching between many other sources, including coverage.

The decoder section of the decoder / synchronization / switching device installed at each receiving location separates this coded data from the interval of vertical blanking of the primary video signal so that it can be used for control and information. In addition, the primary video signal (without data) is provided for viewing by the subscriber.

A microcomputer included in the decoder / synchronization / switching device performs appropriate switching between primary and various secondary video and audio program inputs in response to the data, as well as starting, stopping and receiving the video tape device. Performs various control functions such as machine tuning, operation of alarm devices and status display devices.

By assigning a unique address to each decoder device,
Commands and information can be transmitted to a particular receiving location. Instructions addressed to other receiving locations are ignored.
Group address mode is also possible, which allows
A single instruction can be sent to all receiving locations within a particular area, or in global address mode a single instruction can be sent to all receiving locations in the system.

In addition to sending data to perform the required switching and control functions at the cable system receiving location, it is also possible to send instructions to update the information stored in the storage of the decoder microcomputer. Also, textual information and other forms of data can be sent from the central facility.

A typical national system is divided into regions, each local cable device being supplied with the same national primary news broadcast and regional news broadcasts tailored for a particular region.

Local news producers send their signals from various geographical locations to satellites. Each regional uplink station is equipped with a receiver which supplies the primary signal to the decoder / synchronization / switching device of the regional uplink station similar to that used by the cable equipment. Since each decoder / synchronization / switching device is given a unique address, it is possible to send a specific command to each regional uplink station to instruct it to power up or power down. Since different regional uplink stations use the same regional transponder at different times, and this transponder must not be double illuminated, adjust the operation between regional uplink stations as described above. This is very important. After power-up, the local uplink station has a "local" cable system for the area.
You will also be given an "on air" indication, which means that it is switched on.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Example FIG. 1 shows a television system comprising a central uplink facility 20, a plurality of local subscriber receivers 60 each including a decoder 70 and a number of regional uplink stations 50.
System 10 is shown. The central uplink facility encoder 30 is a local subscriber receiver 60 and regional uplink station.
Linked to 50 and. The communication link between the central uplink facility 20, the regional uplink station 50 and the regional subscriber receiver 60 can be realized by the satellite communication link 100.

The data transmitted by the primary video signal to each decoder of the local uplink station 50 and the local subscriber receiver 60 is scheduled using the PDP 11/23 data processing computer 22. The CRT terminal 24 displays the status of the system and is used for changing the schedule or canceling manually and inputting special commands to be executed immediately. The resulting data, consisting of address data and instruction data, is sent in real time, typically in response to the time of day clock 26, from data processing computer 22 to microcomputer 32 of encoder 30. The contents of the transmission data are also transferred to the printer 28 for automatic recording.

The microcomputer 32 of the encoder 30 is a commercially available 6502.
Configuration by using a View microprocessor, a suitable input / output interface, random access storage and erase / programmable read-only storage,
The program of the microcomputer may be stored in an erasable / programmable read-only storage device. The microcomputer 32 converts the received data from the computer 22 into binary information composed of a pulse width modulated pulse train supplied to the video / data addition circuit 40 of the encoder 30. Microcomputer 32 not only receives and stores data, but also performs some real-time encoder functions programmatically, which would otherwise require additional hardware.
In view of how the microcomputer 32 is interfaced to other encoder hardware, the characteristics of the encoded data, such as the type of pulse modulation used, the grouping and location of address and command pulses in the television field. Many are determined by the programming of the microcomputer 32. In this embodiment, the data is encoded in 6 groups of pulse width modulated pulses as shown in Figure 6A. Each group follows one of the six trailing edge equalization pulses during the vertical blanking interval.

In the pulse grouping format shown in FIG. 6A, the first two groups represent the address of the regional uplink station 50 or the local subscriber receiver 60, and the remaining four groups of pulse data are the designated regional uplink stations 50. Or it contains instructions or information to be transmitted to the local subscriber receiver 60.

Adder circuit 34 receives the data pulse and enters the primary television
Combine with video signal.

The primary video signal transmitted from satellite 100 to decoder 70 of regional uplink station 50 or local subscriber receiver 60 is provided to video / sync / data signal circuit 72 of decoder 70. Video / sync / data signal circuit of decoder 70
72 is a random access storage device as a typical example,
Erasable / programmable read-only storage and appropriate on / off
It is interfaced to a microcomputer 80, shown as a commercial microprocessor 6502A in combination with an output interface. The microcomputer 80 is also interfaced with an electrically erasable and programmable read only memory device 86. Microcomputer 80
The program can be stored in an erasable / programmable read-only memory device or an electrically erasable / programmable read-only memory device 86.

The address of the local subscriber receiver 60 may be set manually by the address switch 82. Other address information can be stored in the storage device 86. If the address pulse data of the data received by the decoder 70 matches the address of the subscriber unit, the microcomputer accepts the command pulse data as to be executed. Microcomputer 80 not only executes receive commands, but also performs some program-controlled real-time data decoding functions that would normally be implemented in hardware.

The video / sync / data signal circuit 72 has the following functions. First, it acts as a conventional television sync separator or sync clipper to provide a composite sync signal to the microcomputer 80 of the decoder. Second, it separates the data from the primary video signal and sends it to the microcomputer 80. Third, it erases the data pulse from the video signal.

Data separation and erasing are enabled by control signals supplied from the microcomputer 80 to the video / sync / data signal circuit 72, respectively. The exact timing of this control signal relative to the primary video signal is calculated by the microcomputer 80 with reference to the separated composite sync signal. Thus, the location in the television field where the decoder attempts to decode the data (usually somewhere in the vertical interval) depends on the programming of the microcomputer 80 and not on the decoder hardware.

The data erase pulse provided by the microcomputer 80 is used in the video / sync / data signal circuit 72 to remove data from the vertical blanking interval of the video signal. The video signal lacking the data pulse is available at the local device and provided as one input to the video / audio switch 74.

Microcomputer 80 processes and evaluates the command data identified by the proper address and initiates the appropriate control output response, including selection of the appropriate video and audio programs supplied as input to video / audio switch 74. To do. Video / audio switch 74 in response to a switch control signal from the microcomputer 80.
A series of video and audio programs transmitted by the company are provided to cable subscribers within a designated area.

By controlling the exact time at which the instruction to switch the video section of the video / audio switch 74 is executed, the microcomputer 80 will switch in the vertical interval whenever it switches from primary video to another source. Can be done. Image distortion is suppressed as much as possible by switching during the vertical interval of the preceding source. The primary composite sync signal, already interfaced to the microcomputer 80 to decode the data, is
To provide the necessary timing information to the data decoder. If the switching between the input video signals is not synchronous with each other, then the synchronizing signals from the other input video signals must be interfaced to the microcomputer 80 so that switching is performed at vertical intervals in all directions.

The video / audio switch 74 is a relay switch. The relay coil is driven by the driver adjacent to the parallel port output bit from the microcomputer 80. Use a small high-speed relay. Because the relay turn-on and turn-off delays are relatively constant, microcomputer 80 can predict this delay when vertical interval switching is required.

In addition to the primary video signal input transmitted from the central uplink facility 20 via satellite 100, regional uplink stations 50
Also via satellite 100, and many local program sources can provide program input to video / audio switch 74 directly. Microcomputer 80 is also programmed to actuate video recorder start / stop mechanism control relays 88 and the like by issuing output signals in response to command pulse data. Front panel lighting indicator 84 decoder 70
Display the operating status of.

For convenience of explanation, the system 10 of FIG. 1 is for a news network, and the primary news service from the central uplink facility 20 may also include one or more regional uplink stations 50 and regional regional program sources. It is assumed that switching and time allocation have been made so that they can be adapted to news services. A typical sequence performed by command data pulses inserted in the vertical blanking interval is about 4 hours after the hour.
At the time of 40 minutes, the central uplink facility 20 sends a power-up standby signal to the local uplink station 50, which is scheduled to broadcast the next local news. After 30 seconds, a power-up signal is sent. After an additional 50 seconds, or 6 minutes after the program, the decoder 70 is switched to the local program input in response to the command data pulse, and the local uplink station 50 is provided with a program start queue. Immediately before the end of the local news being broadcast, a standby signal is sent to the next group of regional uplink stations. At the end of the local news segment being broadcast, an instruction is sent to return all decoders 70 to the primary video news broadcast, and a power down signal is provided to the local uplink station 50 which has just completed the local news program. The power-up signal is then sent to the next regional uplink station group 50. The same sequence is repeated for other areas.

By using special instructions, new types of instructions and other software modification-related programming can be transferred to and electrically downloaded to the electrically erasable and programmable read-only memory 86. This allows the central uplink facility 20 to change the program storage of each regional decoder 70 almost instantaneously.

The encoder 30 schematically shown in FIG. 2 mainly includes a microcomputer 32 and a video / data addition circuit 40.
The video / data summing circuit 40 includes a video amplifier 42 which amplifies the incoming primary television video feed signal and supplies this amplified signal as an input to a sync signal clipping circuit 43 and a summing circuit 44. The clock pulse from the microcomputer 32 acts through the OR gate 45 to input the pulse width modulation command pulse data formed by the microcomputer 32 into the shift register 46.

The data and clock inputs to shift register 46 of encoder 30 are interfaced to microcomputer 32 so that microcomputer 32 can load shift register 46. Microcomputer
Shifting the bit pattern that accurately represents the waveform of the coded signal combined with the video signal in adder circuit 44.
Preload register 46. The video / data signal thus obtained is amplified by the amplifier 48 and supplied to the satellite system 100. When it is time to output the coded signal, the data output enable signal from the microcomputer 32 is generated from the high speed clock oscillator 47, which acts through the OR gate 45 to shift register 46.
To shift the signal waveform at an appropriate speed. The microcomputer 32 can preload the shift register 46 at a relatively low speed in the effective image portion of each field.

For convenience of explanation, assume that the microcomputer 32 must transmit the binary message 010101100 using a coding scheme in which a narrow pulse represents a logic 0 and a wide pulse represents a logic 1. The program of the microcomputer 32 changes the data bit pattern of FIG. 4A to 4B.
Convert to the illustrated shift register bit pattern or waveform. Microcomputer for each data bit
32 flips the logic level sent to shift register 46. The number of bits in the shift register used to represent a particular data bit determines its width and thus the coded value. In the waveform examples of FIGS. 4A and 4B, the width of the wide pulse is just twice as wide as the width of the narrow pulse, but it suffices that an adjustment relationship be established between the wide pulse and the narrow pulse. The ability of the microcomputer 32 software to detect how many pulses can be grouped in a given time interval and control each pulse group to start and end at a binary level corresponding to blanking. Also has.

If the pulse data appears in multiple pulse groups and a pause period is provided between the groups to avoid interference with portions of the television waveform, such as equalized pulses, then stored in shift register 46. The microcomputer 32 is programmed to provide a series of "no signal" bits at the proper locations in the pulse waveform being generated. Therefore,
The pulse group and the rest period between the groups form a single waveform pattern which is pre-loaded from the microcomputer 32 into the shift register 46 which shifts when the microcomputer 32 issues a data output enable signal. Clock from register 46
Will be out.

The microcomputer 32 detects the vertical sync signal in the composite sync signal supplied from the sync signal clipper circuit 43, delays it by a preprogrammed amount, and then
A high speed data clock pulse is generated from the clock circuit 47 by outputting the data output enable control signal at an appropriate point in time, and a pulse train is operated via the OR gate 45 to clock the silt register 46. The high-speed clock pulse train clocks the data waveform stored in the shift register 46 to the adding circuit 44 via the waveform shaping circuit 49, and the pulse data is supplied from the video amplifier 42 to the adding circuit 44 in the adding circuit 44. Is linearly added to the primary television video feed signal. The video / data combination signal thus obtained is a video amplifier.
It is processed by 48 and transmitted via satellite 100 to a local uplink station 50 and a remote decoder contained in a local subscriber receiver 60.

Thus, the microcomputer 32 loads the shift register 46 at a relatively low speed with binary information 1 and 0 which ultimately serve as command pulse data to be added to the television signal. For the composite sync signal from sync signal clipper 43, the clock pulse from clock circuit 47 is detected when the correct timing is detected by microcomputer 32 within the vertical blanking interval of the primary television video feed signal. In response, microcomputer 32 clocks out data from shift register 46 at a constant high speed. The data stored in shift register 46 is a waveform formed by microcomputer 32 in response to binary 1's and 0's of commands received from computer 22. Therefore, the data clocked from the microcomputer 32 to the shift register 46 does not consist of 1s and 0s, but of pulse width modulated waveforms representing the binary data produced by the computer 22.

The waveform shaping circuit 49 controls not only the shape of the pulse but also the rise and fall times of the pulse. The adder circuit 44 is an analog circuit that linearly adds the pulses to the video.

FIG. 3 shows a block diagram of an embodiment of a video / data separator 72 functionally interfacing with a video / audio switch 74 and a microcomputer 80.
It is shown in the diagram. The primary video / data signal having the waveform of FIG. 6A transmitted from central facility 20 via satellite 100 is received by decoder 70 as an input to amplifier circuit 90. The amplified video / data signal is provided as an input to sync signal clipping circuit 91, data clipping circuit 92 and data erasing circuit 93. The function required of the active clamp circuit 94 is to maintain the DC level of the video / data signal and keep the signal level constant in order to remove the pulse data information and insert the correct blanking level. The sync signal clipper 91 separates the composite sync signal from the video / data signal, and the separated composite sync signal is supplied to the microcomputer 80 as an interrupt and a read signal. The software of the microcomputer 80 detects the presence of a valid vertical sync pulse, delays it by an appropriate interval, then generates a data enable pulse, and outputs the pulse data from the data clipper circuit 92.
Transfer to the edge detector via the AND circuit. As long as the data decoding rate is greater than or equal to the reading rate of microcomputer 80, the data will be provided to shift register 97. The data clipper circuit 92 is adjusted so that the video signal is clipped at a predetermined level between the data pulse ends. Due to the timing of the data enable pulses, the only information provided to the shift register 97 is the data and does not include the transient portion of other features of the video / data waveform associated with the clipping operation of the data clipper 92. A waveform of information supplied as an input signal to the edge detection circuit 96 is illustrated in FIG. 5A. Edge detection circuit 96 responds to the edges of the waveform of FIG. 5A, ie, rising and falling transitions, to form a pulse for each transition. The width of the pulse generated from the edge detection circuit 96 is relatively small as shown in the waveform chart of FIG. 5B. The output of the edge detection circuit 96 is used for decoding the data. The purpose of the decoder 70 is to represent the "wide" and "narrow" of the pulse width modulated data transmitted by the vertical blanking interval of the video / data signal and received by the amplifier 90. The terms "wide" and "narrow" as used herein refer to the relative amount of time between consecutive transitions in a coded data waveform. OR
The output of the edge detection circuit 96, which acts through gate 98, is
Clock or shift each value of the decoded data into shift register 97 by one shift register bit position. One bit of the decoded data is stored in shift register 97 for each transient in the transmitted pulse waveform.

The data input of the shift register 97 is the edge detection circuit 96
Corresponds to the output of the retriggerable monostable pulse generator circuit 99 which is triggered by the edge pulse output of. The synchronization of the monostable pulse generation circuit 99 is set between the "narrow" time Tn and the "wide" time length Tw. After the retriggerable monostable pulse generation circuit 99 is triggered by an edge pulse, when the second edge pulse appears at time Tn, the output of the monostable pulse generation circuit 99 remains unchanged at the time of this second edge pulse. Maintained, but "wide" after the retriggerable monostable pulse generator 99 is triggered by an edge pulse
When the second edge pulse appears at time Tw corresponding to time, the monostable pulse generator circuit times out and the second
Returns to the off state before the pulse appeared. That is, the circuit
In the waveform of FIG. 5C corresponding to the output of 99, the output of the retriggerable monostable pulse generation circuit 99 goes high or low depending on the time interval between successive edge pulses. Therefore, depending on the amount of time elapsed between successive pulses supplied to the circuit 99, a data value corresponding to a logic 1 or a logic 0 is shifted in the shift register 97 for each edge pulse.

The waveform of FIG. 5A is a coded data signal which, when supplied to the edge detection circuit 96 of FIG. 3, becomes a pulse output waveform composed of relatively narrow pulses as shown in the waveform diagram of FIG. 5B.
This corresponds to each transient in the waveform of Figure 5A. 5B
In the waveforms shown, the coded digital information is in timing between successive pulses. Therefore, the output of the monostable circuit 99 represented by the waveform in FIG. 5C is the decoded data output.

The same pulse output of the edge detection circuit 96 is used for the trigger of the monostable circuit 99 and the clock of the shift register 97, so that the output can be read before the reset effect by the trigger of the monostable circuit 99 appears on the output. Circuit delay must be set. If no delay is obtained with normal circuit propagation time, a small time delay may be added somewhere in the signal pulse of the monostable circuit.

By utilizing the small finite width of the edge pulse itself, correct timing can be obtained without adding a delay circuit. The output of the monostable circuit 99 may be read at the leading edge of the waveform pulse in FIG. 5B, and the monostable circuit 99 may be triggered in response to the trailing edge.

Microcomputer 80 includes control lines that can also clock shift register 97. The data clock signal from the microcomputer 80 is transmitted to the shift register 97 through the OR gate 98, and the data bits stored in the shift register 97 are transferred to the microcomputer 80 at a speed suitable for the data processing capability of the microcomputer 80. Transmit to computer 80. Microcomputer 80
Performs a parity operation on the data and checks the address. If the address of the data matches the address of the local device, microcomputer 80 organizes the data into a recognizable format and stores it in storage. Received data is video / audio switch 74
Command pulse data to control the memory, or software program modification to download to memory. The updated software information can be downloaded to an electrically erasable and programmable read only memory device 86. The data may be textual material displayed on local monitor 87 to provide information and instructions to a person at local subscriber receiver 60.

The data erasing pulse train shown in the waveform diagram of FIG. 6B is transmitted from the microcomputer 80 to the data erasing circuit 93. The data erasing circuit 93 erases the data pulse from the waveform of FIG. 6A to form an output primary video signal without the data pulse as shown in the waveform diagram of FIG. 6C. The operation of the data erase circuit 93 restores the vertical interval of the primary video signal to its normal state before providing the primary video signal as an input to the video / audio switch 74. Each data erase pulse is initiated by the microcomputer 80 immediately before each burst of data pulses and is terminated before the next equalization pulse appears so that the data pulse is erased but the equalization pulse is Not erased.

In the case of the pulse width modulation method adopted here, the time required to send a message containing a certain number of bits is the content of the message, ie the part of these bits represented by "broad" rather than "narrow". Depends on the proportion of.
The worst case is when the message is all "wide". To enhance data transmission efficiency, the format of the pulse data was chosen so that the pulse representing a given message matched one of two predetermined formats. For a given binary message from computer 22, "broad" represents a logical one or a logical zero, depending on the number of ones in this binary message. For example, if the majority of the binary data received from computer 22 consists of logic ones, the content of logic one of the input binary data is assigned "narrow" and logic zero is assigned "broad". In this way, the transmission efficiency can be increased by setting in advance that the number of "wide" in any message is never larger than the number of "narrow". It should be noted that "broad" and "narrow" refer to the time between successive transitions as previously described in connection with Figure 5A.

The mode bits that appear at some point in the transmission determine the scheme adopted by the decoder. The mode bit may appear at any point in the transmitted pulse data, but for convenience of explanation it is assumed here that the mode bit is the first bit of each transmitted data message.

The microcomputer 32 of the encoder 30 takes a binary data message added to the television video signal and counts all logic 0's and logic 1's, "narrow" to represent the logic level most often appearing in the message. Is assigned, and this is indicated by the mode bit. If the mode bit is "wide," the data message "wide" is a logical zero. The conversion of binary data messages is a function performed by the software of the microcomputer 32.

The microcomputer 80 included in the decoder 70 receives the series of 1s and 0s from the shift register 97 and decodes the logical 1s and 0s contents of the message in response to the mode bits. Microcomputer software can prevent misinterpretation of the space between a certain number of data pulse groups as "data", but if the number of pulses varies from group to group, a special circuit is included for this prevention function. Is desirable. This feature is achieved by using a monostable circuit triggered by the edge detection circuit 96 and configured to time out longer than a “broad” pulse and shorter than the space between pulse groups. You can This time-out effect ends the clocking of shift register 97.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram schematically showing a television system adopting a novel encoder and decoder function according to the present invention. FIG. 2 is a block diagram schematically showing the encoder function of FIG. FIG. 3 is a block diagram schematically showing the decoder function of FIG. 4A and 4B are waveform diagrams showing a pulse width modulation technique for inserting data and information into the vertical blanking interval of the primary video signal by the encoder of FIG. 5A, 5B, and 5C are waveform charts showing transmission data separation and processing by the decoder. FIGS. 6A, 6B and 6C are waveform diagrams showing a format of encoded data information and a pulse waveform for erasing the data information from the transmitted primary video signal. 20 …… Central uplink facility 30 …… Encoder 50 …… Regional uplink station 60 …… Local subscriber receiver 70 …… Decoder 80 …… Microcomputer

Claims (4)

[Claims] 1. A central uplink facility for transmitting to a satellite a primary video signal of a primary video program having data including address and command information inserted in a non-video portion, and a plurality of local subscriber receivers. A plurality of regional uplink stations each transmitting a different video program to a satellite, and receiving the primary video signal and the different video program and transmitting them to a local subscriber receiver, and the primary subscriber station In a satellite communication system comprising a satellite with a plurality of transponders for transmitting a video signal to said regional uplink station, each local subscriber receiving device comprises at least one source providing a video program not via the satellite. By separating the data from the primary video signal, A video decoder device for supplying the following video signal as a separate data output signal and a primary video output signal, and a plurality of video program inputs and one video program output. Video in which the primary video program from the video decoder device is not via the satellite to another one of the video program inputs and to the other one of the video program inputs. A video switching device to which the program is coupled and a video output in response to a data output signal having a specific address and containing the same address from the video decoder device.
One of the video program inputs is included in the data output signal as a video program output of a video switching device provided to a subscriber of a local subscriber receiving device by sending a control signal to the switching device. A computer device for selecting according to command information, wherein each regional uplink station has a video decoder device for supplying this data as a data output signal by separating the data from a primary video signal, and a specific address. And a computer device that operates so that the different video programs are transmitted to the satellite according to the command information contained in the data output signal containing the same address from the video decoder device. From the central uplink facility in the receiver unit Switching between the next video program, separate video programs from multiple regional uplink stations, and non-satellite video programs are all command information contained in the primary video signal from the central uplink facility. A satellite communication system characterized in that it is controlled based on. 2. The satellite communication system according to claim 1, wherein the non-video portion of the primary video signal is a vertical blanking interval. 3. The satellite communication system according to claim 1 or 2, wherein the data output signal sent from the video decoder device to the computer device is a video program output of the video switching device. Including instruction information for controlling the sequential selection of video program inputs, information for updating program information stored in a computer device, and operator information visually displayed at a local subscriber receiving device. Satellite communication system. 4. The satellite communication system according to claim 1, wherein the data inserted into the non-video portion of the primary video signal has a predetermined time between rising and falling transitions of a pulse waveform. The video decoder device comprises a retrigger having a pulse width duration corresponding to the predetermined time, the pulse width modulated waveform representing a first binary value if longer and a second binary value if shorter. Of a possible monostable pulse generator, an edge detection circuit that generates an output to trigger the retriggerable monostable pulse generator in response to a pulse width modulated waveform, and a retriggerable monostable pulse generator A shift register for coupling the output data output signal to the computer device such that the shift register is accessible to the computer device. Satellite communication system stores data output signal, the said computer apparatus characterized by transferring the data output signal from the retriggerable monostable pulse generator circuit to the shift register.