JPH0516237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a terminal polling method in a CATV system.

Conventional configurations and their problems In recent years, CATV systems have been increasingly put into practical use mainly in the United States, and the number of terminals connected to the systems is also increasing.

In a conventional CATV system similar to the embodiment of the present invention, the usage status of all terminals is aggregated at a center.
When processing, each terminal is assigned an individual address, and the center polls the terminals one by one.Only the terminals selected by polling can record their own usage status (TV power on/off, etc.). Channels currently being viewed, information on pay program charges, etc.) were notified to the center. However, with this method, as the number of terminals increases, the polling time for one round of all terminals becomes longer, causing problems in system operation, and in order to further shorten the polling time, it is necessary to increase the transmission speed. However, there were problems such as an increase in the cost of communication equipment and the occurrence of transmission errors.

Purpose of the Invention In view of the above-mentioned problems, it is an object of the present invention to improve the efficiency of polling a large number of terminals without increasing the transmission speed by thinning out the polling of terminals according to the usage status of the terminals. .

Structure of the Invention In the present invention, the center computer receives the power on/off status of the television receiver of the terminal every time polling is performed, and the center computer receives the power on/off status of the television receiver of the terminal.
If the TV receiver is not turned on, that is, the terminal is not currently in use, polling is skipped an appropriate number of times thereafter, thereby shortening the polling cycle for the terminal currently in use and improving polling efficiency. .

DESCRIPTION OF EMBODIMENTS As an embodiment of the present invention, a case where the present invention is applied to a hotel will be described below. Figure 1 shows the system configuration. Broadcasting center 100 and terminal devices 5 in each guest room
00 are connected via a transmission line 400. Broadcast center 100 and hotel center 200 are connected via model 112 and cable 14. Furthermore, the broadcast center 100 and the front terminal 3
00 is connected via a cable 15 and a cable 22. The broadcasting center 100 is comprised of a center computer system (hereinafter abbreviated as center CPU) 110, a source group 120 for video and audio information, a video and audio switching device 130, a head end 140, a modem 111, and a modem 112. Further, a signal from an antenna 150 installed outside the hotel for receiving commercial television broadcasting is input to the head end 140 via the cable 24. Signals from external information sources 160 are also input to headend 140 via cable 25 . The center CPU 110 includes a computer, a display device, a magnetic disk device, a floppy disk device, a magnetic tape device, a line printer device, a card reader device, and the like. The source group 120 is the independent broadcasting studio device 12
1, a video tape recorder 122, a video disk player 123, a character/graphics generator 124, etc. The source group 120 and the video/audio switching device 130 are controlled by the center CPU 110 via the cables 11 and 12. Various video and audio signals from the source group 120 are connected to the cable 2
1 to the video/audio switching device 130,
A video/audio signal selected by the video/audio switching device 130 based on a control signal from the center CPU 110 is input to the head end 140 via the cable 23 . In addition, the center CPU 110 and the terminal device 500
In order to perform bidirectional data transmission between
11 and a cable 13.
The head end 140 has a function of modulating various input video and audio signals, a function of mixing the modulated video and audio signals with a modulated data signal from the center CPU 110, and a function of transmitting the mixed video and audio/data signals to the transmission path 400. Function to output to terminal device 5
It has a function of outputting a modulated data signal sent from 00 via transmission line 400 to center CPU 110 via cable 13 and modem 111.

Hotel sensor 200 is comprised of host computer system 210 and modem 112.
The host computer system 210 includes a computer, a display device, a magnetic disk device, a floppy disk device, a magnetic tape device, a line printer device, a card reader device, and the like.

The front terminal 300 is used to broadcast messages from the front desk to each guest room, and is connected to the center CPU.
It is composed of a front keyboard 310 and a broadcasting source 320, which transmits and receives data to and from 110.
The front keyboard 310 is connected to the center CPU 110 via the cable 15. The output signal from the broadcast source 320 is input to the video/audio switching device 130 via the cable 22.

The transmission line 400 is composed of a bidirectional trunk amplifier 410, a bidirectional branch amplifier 420, a bidirectional branch 430, a series unit 440, and a cable 41.

The terminal device 500 includes a terminal control device 510, a keypad 520 for selecting channels, and a television receiver 530. The terminal control device 510 has the function of transmitting and receiving data with the center CPU 110, converts the frequency of the video and audio signals sent via the transmission path 400 using a channel selection signal from the keypad 520, and outputs the converted signals to the television receiver 530. Has a function. The terminal control device 510 and the keypad 520 are connected by a cable 51. Further, the terminal control device 510 and the television receiver 530 are connected by a cable 52.

Furthermore, the terminal control device 510 converts the block diagram into a third block diagram.
As shown in the figure. The terminal control device 510 is a distributor 51
1, an electronic tuner 512, a modem 513, a terminal control unit 514, an address setting switch 515, a power relay 516, and a power sensor 517.
channel switching of the television receiver 530 by controlling the electronic tuner 512, power on/off management of the television receiver by controlling the power relay 516, detection of key input from the keypad 520, and control of the LED display section 521 of the keypad 520. Perform display output.

Further, the top view of the keypad 520 of the terminal device is as shown in FIG. 2, and 521 is an LED for displaying channel information corresponding to the pressed key;
522 is the request key for paid channels, 5
23 is the request key for the hotel channel group, 5
24 is a request key for a television retransmission channel group, 525 is a response key for confirming viewing when requesting a paid channel, 526 is a channel request key for explaining the operation of the system, and 527 is a power switch.

Note that the receiver, keypad, and terminal control device may be integrated or separate.

The operation will be explained below. First, the center
In order to perform bidirectional data transmission between the CPU 110 and the terminal device 500, one data channel is provided in addition to the video channel, and the downlink data signal from the center CPU 110 is modulated by the modem 111, and then At the head end 140, the data channel signal is mixed with other video channel signals, transmitted to the terminal device 500 via the transmission path 400, and transmitted to the terminal control device 5.
At step 10, the signal of the data channel is demodulated and processed as downlink data from the center CPU 110.

Next, the uplink data signal from the terminal device 500 is modulated by the terminal control device 510, put on the data channel, and transmitted to the head end 140 via the transmission path 400, where the other channel signal is transmitted. The separated data channel signal is transmitted to the modem 111, demodulated by the modem, and then sent to the center CPU 110.

Note that by using different carrier frequencies for uplink data and downlink data, bidirectional data transmission is possible with one transmission channel.

Next, as a transmission method, in order to enable data transmission with multiple terminals, a multi-drop polling method is used, a unique number (address) is assigned to each terminal device, and command data with the address added is sent from the center CPU 110. The data is sequentially transmitted in bit serial format in the format shown in FIG.
Receive bit serial data from 0,
All data is reassembled into the format shown in FIG. 4 and held in memory.

Next, the terminal control unit 514 compares the address part of the held data with its own address read from the address setting switch 515, and only if they match, determines that the data from the center is valid and uses the current command. It performs corresponding terminal processing and sends uplink data from the terminal device 500 to the center CPU 110 in a bit serial format in the format shown in FIG. 4 within a specified time.

An example of commands from the center is shown in FIG.

The operation of the present invention will be explained below. first,
The center CPU 110 notifies all the terminal devices 500 in advance of information for each paid channel, such as the channel number and paid channel classification (G channel, R channel), along with a paid channel notification command. At 510, the sent pay channel information is stored in the memory of the terminal control device 510.

In addition, what G Channel means is that if you watch any one of the paid channels belonging to the G Channel Group, you will be charged a certain amount, and the rest will be charged to G Channel.
It is a paid channel where you are not charged for watching any channel in the channel group, and the R channel is different from the R channel, where the price is different for each channel.
Each channel is independent, and you will be charged a fee whenever that channel is viewed.

After that, when the viewer presses the power switch 527 on the keypad 520, the signal is transmitted to the terminal control section 514, and the power relay 516 is turned "ON" under control from the terminal control section 514.
At the same time that the power of the television receiver 530 is turned on, the electronic tuner 512 transmits the image of a specific channel to the television receiver 530 under the control of the terminal control unit 514.
is output to. Note that at this time, the power sensor 51
7, the TV power-on status can always be detected. Furthermore, since the electronic tuner 512 is directly controlled by the terminal control section 514, information on the channel being viewed can also be held in the terminal control section 514.

Subsequently, when the viewer presses one of the pay channel keys 522 on the keypad 520 to request a pay channel, the signal is transmitted to the terminal control section 514, and the signal is transmitted to the terminal control section 514.
Now, determine whether the requested paid channel is set to G channel or R channel, and if it is G channel, select G channel.
If a channel belonging to a channel group has already been viewed and charged, the video of the requested channel is immediately output to the receiver 530 without performing billing processing, or if the request is for the first G channel group or R channel request. In this case, after performing the viewing confirmation procedure with the viewer, if the pay key confirmation 525 of the keypad 520 is pressed and it is determined that the viewer has an intention to view the video, the billing process is performed and the information is sent to the receiver 530. The video of the request channel is output and the center CPU
110, when the next polling arrives, it sets "1" in the charge generation bit of the status, sets the paid channel data in the channel data, and notifies it.

As described above, in this embodiment, during normal operation, the center CPU 110 collects the usage status of each terminal (TV power on/off, channel currently being viewed, pay program billing information, etc.) by general polling, and uses the information to collect information on pay programs. Automatic duplication to the previous viewing channel is performed when the program is billed, program audience ratings are totaled, or an emergency broadcast ends, or when the device returns from a power outage. In other words, in this system, the television receiver 5
The status of the currently viewed channel and pay program billing information is generated only after the television receiver 530 is powered on, and there is no need for general polling while the television receiver 530 is powered off. So,
Once general polling is applied to all terminals in order,
Judging by the status notified at that time, the next few cycles of general polling will be performed by the terminal 51 whose television receiver 530 is powered on.
Do this only for Note that the number of times the general polling is skipped for the terminal 510 when the television receiver 530 is powered off is determined by the number of times the television receiver 530 is powered on and the terminal control device 51 is started to be used.
The number of times must be sufficient to deal with zero. That is, after the power of the television receiver is turned on, data such as a requested channel number is generated to be transmitted from the terminal control device to the center computer. The number of times general polling is skipped may be set so that by that time, data indicating that the television receiver is powered on is transmitted to the center computer and the state changes to a state in which general polling is not skipped.

Please note that the current billing method is not based on a time-based system, but for paid programs, once you request and start watching, you will be charged a flat rate, and after that, the same fee will apply no matter how many hours you watch. There is no problem even if there is a slight delay in collecting the stored billing information.

Effects of the Invention According to the present invention, unnecessary polling of unused terminals can be reduced, polling of user terminals can be performed more efficiently, and responsiveness can be improved accordingly. Furthermore, the time for one polling cycle can be shortened without increasing the cost or transmission speed of the communication device, which reduces the CPU load and allows other CPU processing to be performed faster.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a terminal polling method in a CATV system according to an embodiment of the present invention.
Fig. 2 is a plan view of the keypad of the terminal device, Fig. 3 is a block diagram of the terminal control device in Fig. 1, Fig. 4 is a diagram showing the communication data format between the center control device and the terminal device, and Fig. 5 FIG. 2 is a diagram showing an example of a command from the center control device. 100...broadcast center, 110...center
cpu, 400...transmission line, 500...terminal device,
510... terminal control device, 520... keypad, 530... television receiver.

Claims (1)

[Scope of Claims] 1. A television receiver, means for turning on/off the power of the television receiver, channel request means, and a terminal control device for controlling the television receiver;
means for turning on/off the power of the television receiver and detecting the requested channel by one polling; a center computer; and a transmission path connecting the center computer and the terminal control device; During one cycle of polling for device data acquisition, each terminal control device is polled at most once, and if the television receiver is powered off at the time of polling, then a predetermined cycle corresponds to that television receiver. A terminal polling method in a CATV system that is characterized in that polling is not performed for terminal control devices that control terminals. 2. If the power of the television receiver controlled by the terminal control device that polled is in an OFF state, the period from the polling to the next polling of the terminal control device The number of cycles in which polling is not performed to the terminal control device is set so that it is the same as or shorter than the period that elapses from when the terminal control device is turned on until data is generated to be transmitted from the terminal control device to the center computer. A terminal polling method in a CATV system according to claim 1, characterized in that: