KR960012505B1 - Digital tv broadcasting switching and monitoring system for optical catv - Google Patents

Abstract

The system includes a synchronizing clock replay and selection means(27,62,64) which is more than one in number for selecting and providing a clock signal, a synchronizing clock distributing means(28,65,67) for distributing and providing single signal to a several ones, a channel broadcasting and uniting means(16,25,26,31,43) for performing a signal multiplex and uniting channels, a supervisory channel selecting means(45,47) for providing single channel signal of the above output signal(16,25,26,31,43) to exterior broadcasting supervisory, and a controlling device(48).

Description

Digital TV (TV) broadcasting switching and monitoring system for optical cable television (CATV)

1 is an overall configuration diagram according to an embodiment of the present invention,

2 is a block diagram of a broadcasting and switching device for one channel according to the present invention.

* Explanation of symbols on main parts of the drawings

16, 25, 31, 43, 26: broadcasting and switching device for channels

27, 62, 63, 64: Synchronous Clock Playback and Selector

28, 65, 66, 67: Synchronous clock divider 45, 46, 47: Surveillance channel selector

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to digital broadcasting switching and monitoring systems for 32 channel television (CATV) signals used in optical cable television (CATV).

In the past, the analog system was used to broadcast a television signal (CATV) on a cable television (CATV), and thus, was easily affected by electrical noise during transmission from a broadcasting station to a home. In addition, the conventional analog TV (CATV) transmission method has a problem that can not use the digital transmission device.

Prior to the present invention, "CATV codec device for NTSC (National Television System Committee) signal having a DS3 (Digital Signal3) transmission rate" (patent application No. 92-13305) is a television (CATV) video for one channel. And an analog / digital (A / D) conversion, compression, multiplexing, and transmission of the audio signal on the transmitting side, and the reverse side of the transmitting side on the receiving side to reproduce television (CATV) video and audio signals, There is no automatic switching function in the event of a failure affecting the service when the broadcasting system is built up, which can lead to the interruption of the broadcasting service and provide a method for monitoring the broadcasting status and the occurrence of the disturbance in the broadcasting operation room. Therefore, there was a problem that can not be used as a real broadcast system.

Accordingly, the present invention devised to solve the above problems is modularized by eight channels in the digital television (CATV) broadcasting for optical cable television (CATV) (in the embodiment, 32 channels will be described). And digital TV for optical cable television (CATV), which has a function of transmitting video signal at DS3 transmission rate per channel and prevents interruption of service in case of a failure during broadcasting, and enables a broadcast operator to monitor the failure and broadcast monitor generated by the broadcasting system. (CATV) The purpose is to provide a broadcast switching and monitoring system.

In order to achieve the above object, the present invention includes at least one synchronous clock reproduction and selection means for receiving a synchronous clock from an external synchronous clock generating device and selecting and providing a clock signal for a channel (CATV); At least one synchronous clock distribution means for decomposing one clock signal received by being connected one-to-one to the at least one synchronous clock reproducing and selecting means to a predetermined number and providing the same; At least one channel broadcasting and switching means for multiplexing a television (CATV) video signal and an audio signal from outside to be synchronized with the synchronization clock provided from the synchronization clock distribution means, and receiving an audio multiple control signal for channel switching; And at least one monitoring channel selecting means for selecting a signal of one channel among the outputs of the at least one channel broadcasting and switching means for monitoring and providing it to an external broadcasting monitoring and control apparatus.

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

FIG. 1 is an overall configuration diagram according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a broadcasting and switching device for one channel of television (CATV).

In the drawing, 1, 2 are baseband NTSC television (CATV) video signals, audio signals, and voice multiple control signals, and 3, 4 are coded by B3ZS in the sync clock generator 29 so that the sync clock playback and selector 27, 62, the same two clocks, 14 are 44.736 Mb / s data output from the codec for channel 32, 15 is the digital television (CATV) broadcast switching and monitoring system for the optical cable television (CATV), 16 Is a broadcasting and switching device for one channel of television (CATV) (broadcasting and switching device for channel 1), 17 is a codec device for broadcasting one television (CATV) channel, and NTSC type television (CATV) signal is converted into digital signal. Codec device that has a data rate of 44.736Mb / s when compressed, 18, 22 is a buffer that amplifies 44.736Mb / s data and is operated by a control unit for switching channel 1 or stopped Tri-state Buffer), 20 Is a broadcast monitoring monitor used to monitor broadcast status, and 21 has a data rate of 44.736 Mb / s and transmits 2.5Gb / s multiplexing 32 data of the same speed as this channel. The optical transmission device 23 is a preliminary channel 1 codec which operates when a failure occurs in the channel 1 codec 17, and 24 determines when a failure occurs in the channel 1 codec 17, and the channel 1 codec 17 A control unit for channel 1 switching, which disables the output of the channel 1 and enables the output of the preliminary channel 1 codec 23, 25 is a broadcasting and switching device for channel 2, 26 is a channel 32 switching device, and 27 is a synchronization device. A synchronous clock reproducing and selecting unit for providing a broadcasting and switching device for one channel of television (CATV) by using the first of the same two clock signals from the clock generator 29 (when the clock signal is lost at the first clock) Loss of Signal) twice 60, 61 are two clock signals, 5, 71, 72, and 73 are selected clock signals, 28 are synchronous clock regeneration and 16 one clock signals provided by the selector are distributed to each channel circuit. The synchronous clock divider provided in the block, 29, has two identical synchronous clock generators (four synchronous clock regenerators and selectors 27, 62, 63, and 64) for transmitting the same clock to the optical cable television (CATV) network. 30 is a baseband NTSC television (CATV) video signal and audio signal input to a 32-channel codec, and 37 and 38 are NTSC control analog video signals for controlling channel 1 switching. A tri-state buffer, which operates by or stops operation, 39 is a distribution signal for distributing an analog baseband NTSC television (CATV) video signal and an audio signal into two, respectively. , 44 is 44.736Mb / s data output from the codec for channel 8, 45 and 46 are monitoring channel selectors each having the function of selecting an output signal for one channel among the output signals of 8 channels, and 47 is channel 1 One channel is selected from channels 8 to 8, and the baseband NTSC television (CATV) video signal and audio signal are output to the broadcast monitoring and control unit 48 (Console). Each of the channel selectors 62, 63, and 64 provides the broadcast and switching device 16 for one channel of the TV (CATV) by using the first signal of the same two clock signals from the synchronization clock generator 29. Synchronous Clock Regeneration and Selector (If the Loss of Signal is lost from the first clock, the second clock is used), 65, 66, and 67 are one clock signal (5) provided by the synchronous clock reproduction and the selector 27, respectively. To disassemble 16 A synchronous clock divider for providing two clocks to each channel circuit block 16, 25, 31, 43 is shown.

The signals input to the channel 1 broadcasting and switching device 16 are baseband television (CATV) video signals and audio signals 1 corresponding to one channel. In addition, the synchronization signal generator 29 receives the synchronization signal 3 from the synchronization clock generator 29 for multiplexing and transmitting a television (CATV) signal for one channel at a DS3 transmission rate, which is a North American transmission standard.

The synchronous clock reproducing and selecting unit 27 uses the first signal from the same two clock signals from the synchronous clock generator 29 to provide the broadcasting and switching device 16 for one channel of a television (CATV). In the synchronous clock reproduction and selector 27, if the clock signal is lost from the first clock (Loss of Signal), the second clock is used.

The synchronous clock divider 28 distributes 16 clock signals 5 provided from the synchronous clock reproduction and selector 27 and provides them to the eight channel circuit blocks 16, 25, 31, 43. The broadcast and switching device 16 for channel 1 receives two clock signals 6 and 59 from the synchronous clock divider 28.

In the signal splitter 39 in the broadcasting and switching device 16 for channel 1, two input television (CATV) signals 1 are made, and then the channel 1 codec 17 and the spare channel 1 codec 23 are used. Enter each in. If the channel 1 codec 17 multiplexes for transmission and monitors broadcasting again, a loss of frame that does not find a frame that may occur during demultiplexing occurs. Of the outputs 10 and 34 become effective.

Its operation is as follows.

When a failure occurs in the codec 17 for channel 1, an alarm signal is generated (40), and the control unit 24 for channel 1 switching makes the outputs of the buffer 18 and the buffer 37 high impedance. The output of the buffer 22 and the buffer 38 is controlled as possible.

When the channel 1 codec 17 or a failure thereof occurs, the output of the preliminary channel 1 codec 23 is a reproduced NTSC video signal, which is transmitted to the broadcast monitoring monitor 20 through the buffer 42. Is displayed. Another output is sent to the 2.5 Gb / s optical transmitter 21 via buffer 19 as data at 44.736 Mb / s (12).

The broadcasting and switching device 16 for channel 1 has been described so far, and eight such circuit blocks are gathered to enable eight channels of digital television (CATV) broadcasting. The monitoring channel selector 47 selects one channel from the channels 1 to 8 and broadcasts the baseband NTSC television (CATV) video signal and the audio signal to the broadcast detection and control device 48. Provide to (Console). Accordingly, by monitoring the control and the broadcast monitoring and control unit 48 by configuring the modules for each of the eight channels can be modularized.

In addition, in order to expand the module for 8 channels, another sensing channel selector 46, 45 is connected to the monitoring channel selector 47 described above as shown in FIG. .

According to the present invention as described above, broadcasting of digital television (CATV) signals is possible in optical cable television (CATV) and the like, and the digital broadcasting apparatus can be used for broadcasting. In addition, the present invention has a function to transmit the TV (CATV) audio and video signals at DS3 transmission rate per channel by modularizing each channel in digital television (CATV) broadcasting for optical cable television (CATV), service in the event of a failure during broadcasting It is effective in preventing the interruption of the broadcast operator and enabling a fault alarm and a broadcast monitor generated in the broadcast system.

Claims (2)

At least one synchronous clock reproducing and selecting means (27, 62 to 64) for receiving a synchronous clock from an external synchronous clock generating device (29) and selecting and providing a clock signal for one channel of a television (CATV); At least one synchronous clock distribution means (28, 65 to 67) for providing a predetermined number of one clock signal which is connected to the at least one or more synchronous clock reproduction and selection means (27, 62 to 64). ; At least one or more multiplexed television (CATV) video signals and audio signals from outside to be synchronized with the synchronous clocks provided from the synchronous clock distribution means (28, 65 to 67), and to receive voice multiple control signals for the entire channel; Channel broadcasting and switching means (16, 25, 26, 31, 43); And at least one channel signal selected from the outputs of the at least one channel broadcast and switching means 16, 25, 26, 31, 43 for monitoring and provided to an external broadcast monitoring and control device 48. A digital television (CATV) broadcasting switching and monitoring system for optical cable television (CATV), comprising monitoring channel selecting means (45 to 47). The signal distribution means (39) according to claim 1, wherein each of said channel broadcasting and switching means (16, 25, 26, 31, 43) distributes and provides two input television (CATV) video signals and audio signals. ); Channel coding means (17, 23) and channel coding means for receiving and compressing a television (CATV) video signal and an audio signal distributed from the signal distribution means (39); Buffering means (18, 19, 22, 38) for switching output signals of the channel coding means and the reserved channel coding means (17, 23) according to a control signal; And a control signal to the buffering means (18, 19, 22, 38) so as to detect an alarm signal from the channel coding means and the reserve channel coding means (17, 23) and to transmit the output of the normally operating coding means. A digital television (CATV) broadcasting switching and monitoring system for optical cable television (CATV), comprising: a control means (24) for outputting.