JPS61148988A - Catv system - Google Patents

Abstract

PURPOSE:To substantially prevent an illegal viewing with the CATV system by providing a counter that comprises three counters to the terminal side to avoid the clearing of chargeable information if any illegality occurs. CONSTITUTION:The TV signal transmitted through the CATV line from the central station is inputted to a TV set 13 via a terminal equipment 12. The counter 14 of the equipment 12 is composed of three counters. The primary counter counts the times of selecting of the chargeable-viewing channels between the telephone protocol start request commands. The secondary counter counts the accumulating number, and the tertiary counts the times of reception. The terminal equipment 12 transmits through the telephone line the chargeable viewing information as well as the counter information to the central station by a request command. The central station transmits through the CATV line a confirmation signal and a feedback of the information from the primary and the secondary counters. The equipment 12 collates this feedback information with the information is the counter 14, and only when they coincide with each other, the equipment 12 clears the chargeable viewing information and the primary counter.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to an OA-V system that uses telephone lines for uplink signals. There is a known system in which upstream data is sent from a terminal to a center using a telephone line using a protocol start request command, and the error information from the terminal is cleared by a command from the center. That is, its configuration is as shown in FIGS. 1 and 2. Figure 1 shows the configuration of the center side of CA TV, in which TV transmitters 1 are prepared for the number of transmission channels, and their outputs are combined and transmitted to the CA TV.
It is sent to each terminal via the TV line. On the other hand, the downlink data signal is output from the computer 3 and sent to the FSK transmitter 2.
The signal is modulated by the above-mentioned TV ratio output and superimposed on it. Further, upstream data signals from each terminal are received by the computer 3 via the telephone modem 4. FIG. 2 shows the configuration of the terminal side, and shows the terminal ia! 12, there is an OATV from the i-interface side.
The l-V signal and the downstream data signal are input via the line. The 1v signal is tuned by the converter 5, reproduced into a regular video by the descrambler 6, and then
'V set 13 is manually operated. A control signal for controlling the converter 5 and the nice clamper 6 is sent from the microcomputer 8, and this control signal is l11w! The downlink data multiplied by the 4-unit (FSK receiver) 7 and the tuning signal from the keyboard 11 are stored in the ROM.
, 10 by processing according to the program written in the program. Then, the paid viewing information written in the RAM of the computer 8 is transmitted to the terminal device 12.
This is a telephone protocol start request command (one of the downlink data) from the center side, and is sent to the telephone line via the telephone modem 9. In such a configuration, T supplied from various video sources
'The V video signal is converted to each TV channel by the V transmitter 1 and sent out. At the terminal, operate the keyboard 11 and enter the desired channel, and the computer 8 will check whether it is a viewing-permitted channel or not. If it is approved, a control signal is sent to the converter 5 and descrambler 6 to tune to the desired channel and descramble it. This makes it possible to listen to RVM. If it is a program, R with power backup
A record is kept that the channel was viewed on AM. Then, on the center side, periodically from computer 3,
A telephone protocol start request command is issued to each terminal. Here, first, a call is made with the address of the subscriber terminal for which paid viewing information is to be collected, and this is called on the terminal 12.
is decoded by the computer 8 of R.
Using the telephone number of the C A TV center written in OM10, the RA is sent as upstream data using the telephone line.
Sends paid viewing information during M. Next, a pay information clear command is sent from the center side, and the pay channel information disappears. The problem here is that if the communication content between telephone modems 4.9 and 4.9 is analyzed, there is a possibility that the next data request will be modified so that lower-cost data is sent. Normal toll collection becomes difficult. [Problems to be solved by R-ming] The present invention has been developed based on the above circumstances, and is based on the above-mentioned circumstances. The present invention attempts to provide a CATV system in which information is checked at the terminal, and if there is any fraud, clearing of the paid information is avoided, and it is possible to substantially prevent eavesdropping.

[Means to solve the problem]

For this purpose, the present invention sends uplink data from the terminal to the center side using the RM telephone line in response to a telephone protocol start request command from the center side, and then clears information on the terminal by a command from the center side. In things,
The above-mentioned terminal has a first counter indicating the number of times the pay viewing channel has been selected between the above telephone protocol start request commands, a second counter indicating the cumulative number of the above counters, and a second counter indicating the above-mentioned 'R telephone protocol start request command reception. A third counter that counts the number of times is equipped, and the above request command causes the information on the above counter to be sent to the center side along with the paid viewing information to the telephone line, and the center side also sends the information on the above counter to the center side via the CA■-V line. Then, the information of the 1st and 21st counters is fed back together with a confirmation signal, and the terminal checks this feedback information with the information of the same counters, and only when they match, displays the paid viewing information and the 1st counter information. The feature is that the counter can be cleared.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to FIGS. 3 to 5. Note that the configuration on the center side is the same as that in FIG. 1, so this is adopted. Further, common parts in FIG. 1 and FIG. 2 are designated by the same reference numerals, and explanations of their configurations will be omitted. However, the difference in structure from the conventional one is that the counter 14 (
(See Figure 3). The counter 14 is composed of three counters, which are configured on the RAM of the computer 8, and are configured according to a program.
Writing and reading are performed. The first counter indicates the number of times the pay viewing channel was selected while the telephone protocol full start request command was issued from the center side, and is normally cleared when a confirmation signal is received. The second counter accumulates the contents of the first counter, and when it overflows beyond a predetermined number, it returns to 0 and continues to accumulate again. The third counter counts the number of times the telephone protocol start request command is received, and like the twenty-first counter, if the counter overflows beyond a predetermined number of digits, it becomes 0.
, and the accumulation continues again. In such a configuration, the process from selecting a pay program at the terminal to writing pay viewing information to the RAM in the computer 8 is the same as in the conventional example. Then, as shown in the timing chart of Fig. 4, the 'rri talk protocol start request command ()'C
G-*1Jhone Ca1l Co1-dnd)
When sent to the terminal, the terminal sends dialing (Q ialing) for the i1 talk to the center side via the telephone line.
Do the following. When the center side receives the dial, it sends an ENQ signal to the terminal, and when the terminal receives the E-NQ signal,
In addition to the terminal address and paid viewing information, the contents of each counter are sent to the center. When the center receives this information, it signals the ACKI number and ends the telephone protocol. After that, the center sends an ACK2 signal on the CA TV line. The paid viewing counter and cumulative counter (first
2nd and 2nd) data is sent to the terminal as is. At the terminal, the two counters sent through the telephone line and C
If the content of the feedback received via ArV line is similar, clear the paid viewing information in AM,
Also, clear the 11th counter. Of course, NAK1
The above information is not cleared when a signal or NAK2 signal is received. The third counter (cyclic counter) is incremented by 1 every time it receives the l-' CC signal. The above three types of counters are composed of 1 byte each, and the RA
It is located inside M and has power backup. Note that FIG. 5 illustrates the format of each command. Therefore, even if the telephone line is modified so that less paid viewing information is sent in the upstream data than it actually is, the center side will determine that some kind of fraud has occurred based on the previous 9 counter value of the cumulative counter and the current counter value. can. On the terminal side, even if the telephone line is modified and the talk protocol is terminated, the viewing information will not be cleared because there is no match when the counter values are compared after receiving the ACK2 signal. It turns out. In general, the communication format of telephone lines is standardized and the frequency is low, so fraudulent acts are easy.
'The V-line SK signal is system-specific, its protocol and format are not publicly available, and its frequency is high, so it is technically quite difficult to modify it. Even if the telephone line is disconnected, uplink data cannot be received for the PCC signal, so the center can detect any abnormalities. Furthermore, when checking the terminal, it is possible to monitor from the cyclic counter how many times the terminal actually received the FCC signal and whether it was in a state where it could not be returned as uplink data.

【Effect of the invention】

As described in detail above, the present invention substantially prevents clearing of viewing information in a system in which upstream data is sent to the center side via a telephone line, even if the telephone line is modified. It has a great effect of preventing it.

[Brief explanation of drawings]

Figure 1 is a block diagram illustrating the transmission/reception configuration on the center side, and Figure 2 is a block diagram illustrating the transmission/reception configuration on the conventional terminal side.
FIG. 3 is a block diagram showing the transmitting/receiving configuration of a terminal according to an embodiment of the present invention, FIG. 4 is a time chart of the same, and FIG. 5 is a diagram showing a simplified protocol and format. DESCRIPTION OF SYMBOLS 1... Transmitter, 2... TOSK transmitter, 3... Computer, 4... Telephone modem, 5... Converter,
6... Descrambler, 1... FSK receiver, 8...
...Computer, 9...'21 Modem, 10...
・ROM, 11...Keyboard, 12...Terminal,
13...r V receiver. Patent Applicant: Pioneer Co., Ltd. Agent, Patent Attorney: Makoto Kobashi, Patent Attorney: Susumu Murai, Figure 1, Figure 2

Claims (1)

[Claims] In response to a telephone protocol start request command from the center side, upstream data is sent from the terminal to the center side using the telephone line,
Thereafter, in the device in which the terminal information is cleared by a command from the center, the terminal has a first counter indicating the number of times the pay viewing channel has been selected between the telephone protocol start request commands, and A second counter indicating the cumulative number and a third counter counting the number of times the above-mentioned telephone protocol start request command is received are equipped, and in response to the above-mentioned request command, the information of the above-mentioned counter is transmitted to the telephone line along with paid viewing information to the center side. At the same time, the center side feeds back the information of the first and second counters together with a confirmation signal via the CATV line, and the terminal collates this feedback information with the information of the same counters, A CATV system characterized in that paid viewing information and a first counter are cleared only when they match.