JPH0779464B2 - Channel management method - Google Patents

Description

The present invention relates to a management system of a video / audio channel connecting a center system of CATV and a subscriber terminal system used in a CATV system.

[Conventional technology]

Conventionally, a video / audio signal is sent from a center system in units of physically defined designated channels, and the designated channels are selectively received by subscriber terminals.

[Problems to be solved by the invention]

In the conventional method described above, when a failure occurs in the transmission equipment of the designated transmission channel of the center system, the corresponding video / audio signal cannot be transmitted, and the subscriber terminal cannot receive the video / audio signal of the designated channel. There is a drawback that you cannot do it.

It is an object of the present invention to provide a channel management system for a CATV system that eliminates such drawbacks.

[Means for solving problems]

In order to achieve the above object, the present invention provides a data input device used for associating a physical channel attribute identifier and a logical channel attribute identifier based on the frequency arrangement of a CATV transmission line, and output from the data input device. Information message destination identifier, physical channel attribute identifier, and
A data processing device for converting and outputting to a message format composed of a logical channel attribute identifier, a data modulator for inputting the message format and outputting a data signal, an active video / audio signal transmitter for outputting a video / audio signal, and a spare video / audio. A signal transmitter, a video / audio signal is input via a switching device, and a data signal is input, and a multiplexer that outputs the video / audio signal and the data signal to the CATV transmission line and the CATV transmission line are output. A distribution unit that inputs a video and audio signal and a data signal and separates the video and audio signal and a data signal, and a data demodulation unit that inputs the data signal and outputs a physical channel attribute identifier and a logical channel attribute identifier,
Input the logical channel attribute identifier you want to view and want to watch the channel switching request information detection unit that outputs the logical channel number, physical channel attribute identifier, logical channel attribute identifier, and the desired logical channel number you want to watch A data processing unit for outputting a physical channel number and a video / audio signal receiving unit for inputting a video / audio signal and a corresponding physical channel number desired to be viewed and outputting a selected video / audio signal to a television receiver are provided.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a frequency allocation diagram of a CATV system to which the present invention is applied. CATV systems are roughly divided into two-way CATV systems and one-way CATV systems. The former is composed of CATV downlink band 2 and CATV upstream band 1, and the latter is composed of CATV downstream band 2 only. The CATV downlink band 2 accommodates the active video / audio channel A by frequency division multiplexing, the downlink data line B of the center system and the subscriber terminal system, and the spare video / audio channel A '. CATV upstream band 1
Accommodates the upstream data line C of the center system and the subscriber terminal system. Therefore, in the bidirectional CATV system, the data communication having the bidirectional communication control procedure can be performed between the downlink data line B and the uplink data line C between the center system and the subscriber terminal system. In the one-way CATV system, non-procedural data communication can be performed using the downlink data line B between the center and the subscriber terminal.

FIG. 1 is a block diagram of a CATV system for explaining an embodiment of the present invention.

To the center device 4, n subscriber terminal devices 11 ₁ , 11 _2, ..., 11 _n are connected via the CATV transmission line 3. The center device 4 is composed of a video / audio system and a control system.

In the video / audio system, the video / audio transmission device 6 is composed of an active video / audio signal transmitter 20 and a spare video / audio signal transmitter 21. During normal service, the video / audio signal 10 for each channel is used.
0 is combined with the data system signal 101 by the multiplexer 5 via the switching device 7 and output to the CATV transmission line 3.

The control system includes a data input device 10 for inputting a CATV channel configuration, a data processing device 9, and a data modulator 8.

The data input device 10 is used to associate the physical channel attribute identifier based on the frequency arrangement of the CATV transmission line 3 with the logical channel attribute identifier. This information is input from the data input device 10 to the data processing device 9 and converted into the message format shown in FIG. 3, and is combined with the channel-specific video / audio signal 100 by the multiplexer 5 as a data signal via the data modulator 8. Downstream of CATV transmission line 2
Is output to.

The message format shown in FIG. 3 includes a message destination identifier 50 and a channel attribute identifier 51 _J (J = 1 to 1).
n) and. A specific code indicating that the message destination identifier 50 is common to all subscribers (simultaneous command) is written. The channel attribute identifier 51 _J is composed of a plurality of pairs of physical channel attribute identifier 55 _J (J = 1 to n) and logical channel attribute identifier 56 _J (J = 1 to n).

The physical channel attribute identifier 55 _J is based on the frequency arrangement of the CATV transmission path 3 and corresponds to the channel arrangement used for normal television broadcasting. Generally, it is specified by 1 to 3 (low band), A to J (mid band), 7 to 12 (high band), J to W (super band), and AA to JJ (hyper band). That is, this information is transmitted by frequency-multiplexing the CATV transmission line 3, and the subscriber terminal device 11 _J (J
= 1 to n). The video / audio signal 102 is the video / audio transmission device 6 of the center device 4,
It corresponds to the natural frequency of each of the active video / audio signal transmitter 20 and the spare video / audio signal transmitter 21. That is, a unique physical channel attribute identifier 55 corresponding to the active video / audio signal transmitter 20 and the spare video / audio signal transmitter 21.
_J is given.

On the other hand, the logical channel identifier 56 _J indicates the subscriber terminal device 11 _J.
It is an individual channel number for selection that each subscriber wants to watch on the television receiver, and in general, it is easy for the subscriber to operate by specifying the channel number.

In order to implement the present invention, as described above, the physical channel attribute identifier 55 _J that defines the broadcasting system and the logical channel attribute identifier 56 _J that defines the unmachine of the user, that is, the channel selection are defined.

In FIG. 1, a video / audio signal and a data signal passing through the downlink band 2 of the CATV transmission line 3 are distributed to the data signal 101 and the video / audio signal 10 by the distributor 12 of the subscriber terminal device 11 _J of each subscriber.
It is separated into two. The data signal 101 is converted into baseband signal data by the data demodulation unit 13, and the channel attribute identifier 51 _J in the format of FIG.
Stored in 4. The video / audio signal 102 is a video / audio signal receiving unit.
All channels are input to 17. When the viewer inputs the logical channel attribute identifier 56 _J that he / she wants to view in the channel switching request signal transmitting section 16, the corresponding channel number is an infrared digital code and the channel switching request information detecting section.
The corresponding logical channel number 104 to be viewed and decoded is input to the data processing unit 14 at 15. Data processing unit 1
4 is the logical channel attribute identifier 56 _J in the channel information identifier 51 _J stored in the data processing unit 14 in the format shown in FIG. To search. The physical channel attribute identifier 55 _J corresponding to the logical channel attribute identifier 56 _J that matches the corresponding logical channel number 104 to be viewed is input to the audio / video signal receiving unit 17 as the corresponding physical channel number 105 to be viewed, and the audio / video signal 10 is input.
2 is tuned to the corresponding physical channel to be viewed and output as the selected video signal 103 to the television receiver 18.

From the above, the center device 4 in the broadcasting system
Even if one of the active video / audio signal transmitters 20 of FIG. 3 is changed to the spare video / audio signal transmitter 21 at the time of failure, the failure in the channel attribute identifier 51 _{J in} the message format shown in FIG. The logical channel attribute identifier 56 _X corresponding to the physical channel attribute identifier 55 _X of the active video / audio signal transmitter 20 is undefined (disabled), and the physical channel attribute identifier 55 _Y of the spare video / audio signal transmitter 21 is set. The corresponding logical channel attribute identifier 56 _Y is changed by the data input device 10 to the data used in the conventional logical channel attribute identifier 56 _X. This data is converted by the data processing unit 9 into a format as shown in FIG.
Via the data processing unit 14 of each subscriber terminal device 11 _J , and, as described above, a predetermined video / audio signal corresponding to the signal of the channel switching request signal transmission unit 16 is transmitted to the television receiver 18 Is output to.

〔The invention's effect〕

As described above, according to the present invention, when the video / audio signal transmitter of the corresponding transmission channel of the center system transmits a video / audio signal by the spare video signal transmitter when a failure occurs, the logical channel of the corresponding channel By transmitting a message with the attribute identifier changed to a spare physical channel attribute identifier to all subscriber terminals by a simultaneous command from the center system, the subscriber selects the channel number used before the failure and displays the image. It has the effect of receiving voice signals and being able to receive services regardless of the operating status of the center system.

[Brief description of drawings]

FIG. 1 is a block diagram of a CATV system for explaining an embodiment of the present invention, FIG. 2 is a frequency allocation diagram of a bidirectional CATV system, and FIG. 3 is a message format according to the embodiment of the present invention. 1 ... CATV upstream band 2 ... CATV downstream band A ... Current video / audio channel A '... Spare video / audio channel B ... Data line (down) between center system and subscriber terminal system ...... Data line between the center system and the subscriber terminal system (uplink) 3 ...... CATV transmission line 4 ...... Center device 5 ...... Splitter 6 ...... Video and audio transmission device 7 ...... Switching device 8 ...... Data modulation Device 9 …… Data processing device 10 …… Data input device 11 _J …… Subscriber terminal device 12 …… Distribution unit 13 …… Data demodulation unit 14 …… Data processing unit 15 …… Channel switching request information detection unit 16… … Channel switching request signal transmitter 17 …… Video / audio signal receiver 18 …… TV receiver 20 …… Current video / audio signal sender 21 …… Spare video / audio signal sender 50 …… Message destination identifier 51 _J … ... channel attribute identifier 55 _J ...... physical Chang Le attribute identifier 56 _J ...... logical channel attribute identifier 100 ...... by channel video and audio signal 101 ...... data signal 102 ...... audiovisual signal 103 ...... selected video audio signal 104 ...... wants to view the corresponding logical channel number 105 ... … The physical channel number you want to watch

Claims (1)

[Claims] 1. A data input device used for associating a physical channel attribute identifier based on a frequency arrangement of a CATV transmission line with a logical channel attribute identifier, and information output from the data input device is used as a message destination identifier and a physical destination. A data processing device for converting and outputting to a message format consisting of a channel attribute identifier and a logical channel attribute identifier, a data modulator for inputting the message format and outputting a data signal, and an active video / audio signal for outputting a video / audio signal. Transmitter and standby video / audio signal transmitter, input video / audio signal through the switching device, and then input data signal to convert video / audio signal and data signal.
A multiplexer that outputs to the CATV transmission line, a distribution unit that inputs the video and audio signals and data signals output to the CATV transmission line, and separates them into video and audio signals and data signals, and a physical channel attribute identifier that inputs the data signals. And a data demodulation unit that outputs a logical channel attribute identifier, a channel switching request information detection unit that inputs a logical channel attribute identifier to be viewed and outputs a corresponding logical channel number to be viewed, a physical channel attribute identifier, a logical channel attribute identifier, and ,
A data processing unit that inputs the corresponding logical channel number that you want to watch and outputs the corresponding physical channel number that you want to watch, and a video that outputs the audiovisual signal and the selected audiovisual signal that you input the corresponding physical channel number that you want to watch. A channel management system comprising an audio signal receiving section.