JPH0420316B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a billing method that can be used in a unidirectional signal transmission and reception system such as satellite broadcasting. Conventional configuration and its problems In a unidirectional signal transmission/reception system such as satellite broadcasting, in order to operate the terminal receiver in the same way as when receiving CATV pay programs, it is necessary for the viewer to pay for the viewing fee in a deferred manner. It is necessary to make the viewer pay, and if the viewer does not pay, it is necessary to make the viewer's terminal unable to receive reception. These are implemented in pay television in interactive CATV systems. However, in the case of the CATV system, the system requires the transmitting side to request viewing of pay TV via uplink or telephone, so this cannot be used for a one-way system such as satellite broadcasting. Furthermore, when a large number of subscribers applied to the sending side all at once, the capacity of the telephone line and the receiving processing capacity of the sending side were exceeded. An example of the configuration of such a conventional example is shown in FIG. In the figure, 1 is the center computer of the CATV station, which manages the subscriber's viewing fee payment status, the specification of broadcast programs according to the subscriber's wishes, the creation of control codes, etc., and the CATV center 2 manages the VTR, film, studio, etc. The control code is added to the video signal and transmitted. 3A is the head end,
For example, multiple video signals from CATV center 2
Transmit in line with VHF mid-band. 3B is a buffer circuit that receives upstream signals from each terminal, and the head end 3A and the buffer circuit 3B at the tuner/converter 4 on the terminal side of the CATV are connected by the same cable or another cable. or,
Tuner/converter 4 to buffer circuit 3B
A telephone line may be used instead of a cable. 4 is a tuner or converter on the terminal side that converts the mid-band signal into one channel (or two channels) of VHF, and keypad 5
Converts one channel of the mid-band CATV signal to one channel of VHF according to instructions from the station. Note that if the CATV signal is scrambled, it may be converted to a baseband signal, descrambled, and then converted back to an RF signal and output as a VHF 1-channel signal. 6 is a television receiver that receives normal VHF band reception. A viewer applies for a desired program (charged) to the center computer 1 by operating a keypad 5 or via a telephone 7. At the center 1, charges are set for each terminal, and if the terminal is scrambled, the decoding key code is sent in the order of center computer 1 → CATV center 2 → head end 3 → converter/tuner 4. Then, use this key code to descramble, play the normal image NTSC video signal, convert it to 1 channel of VHF,
It is supplied to the television receiver 6. There are a large number of chainers/converters 4 to telephones 7, and a telephone office is interposed between the telephones 7 and the telephone interface 8. The telephone interface 8 generally allows a human to listen to requests from each terminal and convert them into input form for the center computer 1. This is an example. OBJECTS OF THE INVENTION An object of the present invention is to provide a billing method that can implement a pay television system in a unidirectional signal transmission system such as a satellite broadcasting system. Structure of the Invention In the present invention, in a device for receiving unidirectional television signals such as a satellite broadcasting system, billing information corresponding to the viewing time of a television program and the content of the program is transmitted in the form of a digital signal for a certain period of time. The amount is determined by a charging amount determining circuit in the receiving device of the terminal, and the charging data proportional to the metal is written into a non-volatile memory, and the charging data in the memory is displayed as necessary. In that case, the non-volatile memory is divided into three parts, and the first non-volatile memory stores charge information proportional to the viewing time of each program. The contents of the first memory are added to the contents of the second non-volatile memory each time viewing is completed, and the contents of the second memory are added to the contents of the second non-volatile memory upon receiving the charge display instruction code sent from the sending side at regular intervals. The data is transferred to and stored in the non-volatile memory of No. 3. When receiving data corresponding to the paid charges that are sent separately to each receiving device from the sending side, this data is compared with the contents of the second or third memory, and whether the two are equal or 2. When the contents of the third memory are smaller than the received data, clear the contents of the second and third memories, and the received data
Alternatively, when the amount is smaller than the content of the third memory, the difference is stored in the second and third memories, and the amount of the difference is displayed. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 shows an embodiment of the present invention. In the figure, 11
is a satellite broadcasting transmission center called a DBS center. 12 is a large parabolic antenna that sends signals to a geostationary satellite 13. 13
is a geostationary satellite, a broadcasting satellite that relays signals sent from the ground and retransmits them back to the ground. 1
4 is a receiving antenna installed on the ground. 1
5 is a low noise converter, for example antenna 1
Converts the 12 GHz band received by 4 to 1 GHz band and transmits it to receiver 16. 19 in the receiver 16 is called an intermediate frequency demodulation unit (IDU), and receives input in the 1 GHz band, for example.
Converts to 2nd LF of 400MHz, amplifies, detects, and outputs baseband signal. 20 is a data processing circuit that extracts the output digital signal, processes it, and supplies it to the descrambler 21. Assume now that the video signal is scrambled using a method of synchronous shifting and randomly inverting the video components, and the audio is scrambled using a method of randomly changing the bit arrangement using digital audio. When the output of the IDU 19 is projected as is on the CRT of the color television receiver 17, the brightness of the screen is inverted, and the horizontal and
Since vertical synchronization cannot be achieved, the content flows and the content is unclear. Also, if you listen to the voice as it is from the speaker, it becomes noise. Therefore, the descrambler 21 switches between inverting and non-inverting the video based on the output of the data processing circuit 20, and rearranges each bit of the digital audio signal to restore normal video and audio (descrambler 21). scramble). A/
The V regeneration circuit 22 changes the DC level only during the horizontal retrace period during the output of the IDU 19, that is, the portion from t ₁ to _{t 2} in FIG. ₂ to _t11 to reproduce the original video signal (FIG. 3A), and convert the digital audio signal output from the descrambler 21 into an analog audio signal. The output of this A/V regeneration circuit 22 is transmitted to the RF modulator 2.
Step 3 converts the signal to an appropriate channel in the VHF band,
If the output is supplied to the antenna input of an ordinary color television receiver 17, the scrambled video and audio can be viewed in their normal, descrambled state. If you want to watch such scrambled video and audio back to normal images and sounds, you often have to pay a fee. If there is a charge, the charge is indicated by a control digital signal superimposed on the vertical blanking period (VBL) of the video signal of the program, and the charge is recorded in the memory within the receiver. Generally, if you receive a certain program for more than 2 to 10 minutes, you are often required to pay for the entire program. To pay the fee, for example, add a card reader to the data processing circuit 20 in Figure 2, insert the purchased card (such as a coupon ticket), and check the amount paid. There is a method of sending a descrambling control signal from the data processing circuit 20 to the descrambler 21 only for a time corresponding to the amount of time. Alternatively, you can pay the fee in advance to the bank 18 and use the prepaid fee as data.
A code representing the paid fee is sent from the DBS center 11 to each terminal (individually assigned an address) via the geostationary satellite 13, and the fee code is written in the memory of the terminal. Change (decrease) the rate code in
There is also a method in which when the number reaches "0", the money is paid to the bank 18 again and the above procedure is repeated. Now, here, data processing circuit 2 in FIG.
The contents of 0 are configured as 31 to 50 in Figure 4, and when a pay program is received, the video signal is
Charges corresponding to the viewing time are written to non-volatile memory according to the charge data superimposed on the VBL period, the viewing charges are paid to the bank every month, and the paid charges are polled from the DBS center 11 for each terminal (each address). As long as the contents of the memory 47 do not become "0" by sending it and subtracting the contents of the memory 47,
The system will be such that you will no longer be able to watch paid programs from the next month onwards. In Figure 4, 31 is the VBL output from IDU19.
This is a binarization circuit for shaping the waveform of a binary data signal superimposed on a period to form a pulse waveform as shown in the left end portion of FIG. 5B. 32 is a clock detection circuit which uses the clock run signal CR (Clock Run), which is a repetition of the 2-byte "1" and "0" signals at the beginning of FIG. The framing code is detected at the 8th bit of the framing code signal FC to establish frame synchronization, and the sampling clock generated by the sampling clock generation circuit 33 is synchronized with the received signal B. 33 is a circuit that forms a sampling clock with an appropriate phase controlled in this way, and the output thereof is divided by a main clock generation circuit 34 to be outputted to the work RAM 3.
7. Forms a main clock that drives the work ROM 38, center processing unit (CPU) 39, etc. A clock synchronized with each bit of the received signal shown in FIG. 5B is supplied from the output of the sampling clock generation circuit 33 to the sampling circuit 35, and each bit of the received signal B is sampled. If the pulse width of each bit of the received signal B is 5f _sc /8, it will be approximately 175 nS, and at this period, the work RAM 37 to
CPU 39 is difficult to operate. or,
When an 8-bit microprocessor is used as the CPU 39, it is more convenient to handle the received data as 8-bit parallel signals. Therefore, a serial input/parallel output type shift register such as SN74LS164 is suitable as the sampling circuit 35. If the output is memorized in a latch circuit 36 every 8 bits with the 8th bit of the framing code as a reference,
The output is 8 bits in parallel and changes at a period of 8×5f _sc /8=1.4 μS. This cycle is suitable for the operation of each circuit. Its output is connected to bus line 40. 37 is the work RAM of CPU39, 38 is CPU3
The CPU 9 is an 8-bit microprocessor (for example, MB6809E). Now, the control code C ₀ in the received signal B in Fig. 5,
To explain C ₁ to _{C 7} , C ₀ and C ₁ are "1",
It is a clock run signal CR that repeats “0”,
_C2 is a framing code signal of "11100101". _C3 consists of 4 bits of information, 3 bits of humming check code, and 1 bit of parity. _C4
The data after this also has the same structure for each byte. The contents of the information section of C ₃ and C ₄ are summarized in Table 1. Here, only three types necessary for explanation are described. In reality, several types or more are possible. Similarly, Table 2 shows the contents of the 4-bit information part of _C5 .

【table】

Claims (1)

[Scope of Claims] 1. Billing information corresponding to the viewing time of a television program and the content of the program is received at fixed intervals in the form of a digital signal using a one-way television signal, and the billing information is stored in the reception device of the terminal. The charge amount determination circuit determines the amount, writes charge data proportional to the amount into a non-volatile memory, and reads and displays the charge data in the non-volatile memory as necessary. The charge information proportional to the viewing time of each program is stored in the first non-volatile memory, and the above information is stored each time the viewing of a paid program ends, such as when the program ends, when the power is turned off, or when switching channels. The contents of the first non-volatile memory are transferred to the second
and transfers the contents of the second non-volatile memory to a third non-volatile memory and stores them when receiving a charge display instruction code sent from the sending side at regular intervals; When receiving data corresponding to the paid charges that are sent separately from the sending side to each receiving terminal device, this received data is compared with the contents of the second or third non-volatile memory to determine whether the two are equal or When the contents of the second or third non-volatile memory are smaller than the received data, clear the contents of the second or third non-volatile memory;
When the received data is smaller than the content of the second or third non-volatile memory, the difference is stored in the second or third non-volatile memory and the amount of the difference is displayed. Method. 2. If the received data corresponding to the paid fee, which is sent separately from the sending side to each receiving terminal device, is smaller than the content stored in the third memory of the receiving device, the new data sent from the sending side is 2. The billing method according to claim 1, wherein the receiving terminal device is operated so as not to accept the decryption information. 3 Compare the contents of the second memory of the received data,
When the content of the former is greater than the content of the latter, the difference is stored in the second memory, and a flag is set while the difference is stored in the second memory. , when moving the contents of the first memory to the second memory, the contents of the second memory are added as a negative number, and the result is transferred to the second memory.
3. The billing method according to claim 2, wherein the billing method is stored in a memory.