KR900004958B1 - Inter-communcation system of bi-direction catv - Google Patents

Abstract

The system provides data requested by subscribers and collects data offered by subscribers. A first period for transmitting reguest signal from subscriber to CATV station and a second period for transmitting signal allowing mutual data communication are repeated. Request siganl from other subscriber is prohibited during the first period and signal representing non capability of data exchange with other subscriber is transmitted.

Description

Mutual information exchange system for interactive CATV

1 is a schematic diagram showing the configuration of a two-way CATV SYSTEM information exchange method for transmitting a subscriber number in response to a subscriber's request for information.

2 is a frequency sequence diagram in a transmission path in the mutual information exchange method of the bidirectional CATV SYSTEM according to the present invention.

3 is a flowchart of information exchange between a subscriber and a wired broadcasting station according to the present invention.

4 is a flowchart of a transmission path control for transmitting information between a subscriber and a cable broadcasting station according to the present invention.

5A and B are schematic and schematic circuit diagrams of a subscriber station apparatus for requesting information from the cable broadcasting station and processing information provided from the cable broadcasting station.

The present invention relates to a mutual information exchange system for CATV, and not only to provide information to each subscriber at the cable broadcasting station for each information requested from each subscriber, but also to deal with various kinds of situations occurring at each subscriber. You can collect data.

For example, it is possible to investigate the viewing of each channel of cable broadcasting, and to perform the tasks such as the frequency of the use of gas, water, power, etc., and the prevention and prevention of the information age, so that the above tasks can be unmanned. This prevents subscribers from invading their privacy and provides them with the benefits of a highly scientific age. In addition, as a conventional method of exchanging information, a contention selection method (CONTENTION), each subscriber station requests a transmission line randomly for information request. Therefore, when one subscriber is exchanging information with the cable broadcasting station, the other subscribers are in a waiting state, so the drawback of this method is that each subscriber terminal sends a long code signal when transmitting information, so that the transmission path is long. Since the information transmission of each subscriber occurs at the same time, it is easy to collide, and there are many defects.

Another typical information exchange method in the related art is a sequential call method, in which a voice broadcasting station transmits a sequential call signal asking whether or not there is information to be transmitted to each subscriber, and when each subscriber terminal has transmission information, for example, When you want to watch a specific channel, or when you receive a sequential call signal to your terminal, it sends its information to the voice broadcasting station.

In this case, the call pulses that are sequentially sent arrive at the subscriber terminal and the information of the terminal is sent to the voice broadcasting station. Therefore, there is a fear that the information data is repeatedly transmitted from multiple subscriber terminals. Because of this, the line efficiency of the transmission channel is reduced.

Accordingly, an object of the present invention is to provide a system for installing a large host computer (HOST COMPUTER) on the wire broadcasting station in a two-way CATV SYSTEM and installing a terminal to each subscriber to exchange the information between each other as shown in the accompanying drawings. When described in detail as follows.

Figure 1 combines a plurality of subscriber terminals (hundreds and tens of thousands) with a two-way transmission path (mutual information exchange) that transmits the information required from each subscriber and processes the information transmitted from each subscriber. The configuration of the communication method is shown.

Here, the part enclosed by the dotted line A becomes a cable broadcasting station, and is composed of a plurality of video and audio 1 or data transmission devices 3, which are the same as the conventional CATV SYSTEM. However, it is a feature of the present invention that there is an information number dispensing apparatus 4 here. In addition, the part enclosed by a dotted line (C) represents a plurality of subscriber stations and combines a plurality of subscriber stations (A) and a plurality of subscriber stations (C) by a common transmission path (B).

The common transmission path B transmits information exchanged by the voice broadcasting station side and each subscriber terminal in two directions, which is the same as the conventional two-way CATV SYSTEM. Here, the various types of information transmitted from the cable broadcasting station and the various types of information transmitted from the subscriber terminal have respective carriers for each information by frequency division multiplexing. 2 shows an example of implementing the mutual information exchange channel of the present invention by a frequency division communication method. In FIG. 2, only broadcast waves for information exchange are shown, and not cable broadcasting program channels. In this case, a channel having a bandwidth of 6MHZ arbitrarily in the 5-50MHZ band of the SUB-BAND is called F ₁ and a channel having no broadcast program in the 216-300MHZ band of the SUPER BAND is F ₁ . ₂ , F ₁ is a carrier frequency for each subscriber to carry data to be transmitted to the cable broadcasting station.

Accordingly, channel F ₁ is a channel where each subscriber station requests information required for a wire broadcasting station, and in response, the cable broadcasting station transmits code data about a program channel that the subscriber desires to watch through the F ₂ channel. In this manner, when each channel shown in FIG. 2 is transmitted through the transmission path B, and mutual information exchange of the present invention is performed, an overview thereof will be described with reference to FIG.

In FIG. 3, the subscriber sends an information exchange request signal CD through the F ₁ channel. The cable broadcasting station receives the information exchange request signal (CD). At this time, the cable broadcasting station checks whether the information exchange is possible, and if possible, transmits a polling signal DA for requesting information to the calling subscriber at the transmission frequency F ₂ . Upon receiving the request for information, the subscriber sends the response data DM through F ₁ in response to the polling signal DA. In addition, in FIG. 3, the other subscriber generates a communication prohibition signal (D ₁ ) to prohibit the subscriber from transmitting the information exchange request signal (CD).

When the mutual information exchange is completed by the above procedure, the cable broadcasting station sends a subscriber communication enable signal (D ₂ ) for canceling the communication prohibition signal that the information exchange request is possible to each subscriber.

The following describes the procedure of transmission path control for information transmission between the subscriber and the cable broadcasting station of FIG.

In FIG. 4, the part surrounded by the dotted line (C) shows the signal transmission and reception form in the subscriber terminal, and the part surrounded by the dotted line (A) shows the signal processing, transmission and reception form in the cable broadcasting station, and the solid line ( It shows that time passes in the direction of a).

This indicates an operation procedure according to the first form of the subscriber is sent to the operation when the subscriber terminal (C) when you want to watch a particular channel request information exchange through a subscriber transmission line signal F ₁ (CD).

(Operation Procedure 1) At this time, the information exchange request signal (CD) finds its address code in the subscriber address memory of the cable broadcasting station. That is, the subscriber station (C) operates the channel selection switch, and at the same time, the mutual information exchange system starts operation to generate a carrier frequency corresponding to the channel F ₁ , and phase modulates the data pulse of its own address code. FSK) and transmit it through the channel F ₁ to receive it from the cable broadcasting station A. (Operation Sequence 2)

The cable broadcasting station (A) searches for a BUFFER RESISTOR (BR), which will be described later, and closes the gate (G) to wait for the information exchange request signal (CD). If G) is opened and sent to the buffer register, the buffer register BR writes the subscriber address code requesting information exchange to the subscriber address memory (Operation Step 3).

At this time, in order to prohibit other subscribers from exchanging information, the gate G is closed to refuse reception.

According to the calculations of the present inventors, if 2400 subscriber stations (C) are connected to the cable broadcasting station (A), when each subscriber calls 10 times a day, the information exchange time per call is estimated to be about 1 second, For the loss rate to be 0.0015%, the number of address codes stored in the buffer register BR should be about four.

Therefore, the number of data records of the buffer register BR using the method according to the present invention is determined corresponding to the number of channels of the information switching line, so that the overall system efficiency is increased. On the other hand, when the search for the buffer register BR is completed and mutual information exchange is possible, a polling signal is generated to set a subscriber address, and the information exchange is approved. At this time, the polling signal DM is polled by the common control channel F _2. Is transmitted via (Operation Sequence 4).

In addition, when the operation procedure 4 is terminated, other subscribers transmit the call prohibition signal D ₁ to the subscriber terminal C in order to prohibit the information exchange request. In addition, the subscriber station C requests data required to open an information code that can be provided in the information memory BM, and is also transmitted through the common control channel F ₂ . )

Upon receiving this information, the subscriber station (C) sends out information code-in response data (DM) for the necessary information and analyzes it in the cable broadcasting station (A) to determine whether the information required by the subscriber can be provided. Search in (BM). (Operation Procedure 6)

At this time, the retrieved information is sent to the subscriber station (C).

When such a procedure is completed, the call prohibition release signal D ₂ is sent to all other subscribers, indicating that they may request information exchange.

The following describes the configuration of the subscriber station 5a, b. In order to exchange information with the cable broadcasting station, if the data in the form of phase-modulated data on the channel F ₂ , which is commonly controlled by the cable broadcasting station, is applied to the demodulator (DEMOD) through the band pass filter (BPF), the carrier is And data signals are separated and accumulated in the register REGI. The accumulated data is decrypted to a LOGIC and the required signal is output. In addition, when a channel to be watched is input to the channel select switch KB, it is accumulated in the shift register SFTREG.

When the subscriber station requests watching a specific channel to the cable broadcasting station through the F ₁ channel, when the channel selection switch (KB) is pressed, the AND gate (AND ₁ , AND ₂ ) is prohibited from communication by the flip-flop (FF ₁ ). Only when the period is out of time, the address data stored in the register REG ₁ is read out and carried on the F ₁ carrier which can be transmitted while passing through the modulator MOD.

When the call charge prohibition signal (C ₁ ) is sent from the cable broadcasting station, a positive signal is applied to the (C ₁ ) terminal of the data processing device (LOGIC), and the AND gate (AND ₁ ) is activated (ON). AND ₂ ) is OFF-OFF. When the channel select switch KB is pressed, the data is waited for the call charge prohibition period by the delay circuit DELAY through (AND ₁ ).

As a result, the delay circuit (DELAY) is involved even during the call charge prohibition period, so there is no loss of data, and when the call release signal (C ₂ ) is sent from the cable broadcasting station, the register (REC ₂ ) is transmitted through the delay circuit (DELAY). This address data is immediately sent to the modulator MOD.

In the output terminal 3 of the processing device LOGIC, a channel selection signal appears and the corresponding channel data stored in the channel code storage device CH and COD is read out and then passed through the digital / analog converter D / A to the channel selector F. ) Determines the channel of the TV receiver by outputting a DC voltage corresponding to the local oscillation frequency of the corresponding channel.

On the other hand, when the channel code storage device CH and COD are accessed by the register REC ₃ and the channel code storage device CH and COD release the corresponding channel code, the code value is transferred to the modulator MOD so as to pass low pass. It is loaded on the transmission channel F ₁ via a splitter SPL through a filter LPF.

5b shows a schematic diagram of a subscriber station.

SPL in Fig. 5b is a splitter for separating the input signal and the output signal, DEMOD is a double period for demodulating the data on the carrier of the input signal F ₂ and DEC determines that the signal to be received is rejected for the stimulus, When the signal is generated, it is a north lake circuit that generates an output.

The channel selection switch (KB) is used to input data for the subscriber to request a viewing channel, and CH and COD are memories that encode a transmission signal and store it as a code value.

The coded channel code storage circuits CH and COD include a control circuit, a memory circuit, a signal conversion circuit, and the like. The transmitted data value requires a modulator (MOD) to modulate at the F ₁ frequency, and the gates G ₁ and G ₂ are circuits for call prohibition and release. In case of requesting information exchange, it is possible to press the channel selection switch (KB) and at the same time when there is no call with non-subscriber. , COD).

According to this input code, the information code unilaterally stored in the panel code memory circuits CH and COD is modulated by the modulator MOD, and then through a splitter via a gate G ₂ and a low pass filter (LPF) to the cable broadcasting station. Is sent out. At this time, however, the gate G ₁ is closed by the (C ₁ ) signal detected by the demodulator (DEMOD) when the information is exchanged with another subscriber, so that the call prohibit release signal (C ₂ ) is waited to be received.

If the cable broadcasting station sends a call suppression signal (C ₂ ) to the decoder (DEC) through the demodulator (DEMOD), it opens the gate of (G ₁ ) when it matches its address and waits in the channel code memory circuit. The information being sent is output and sent out.

In this way, the present invention not only can provide information to each subscriber, but also reduce the number of long signals transmitted during information transmission, thereby eliminating collisions occurring at the same time, and also transmitting call pulses from the cable broadcasting station. This also increases the circuit efficiency of the transmission channel.

Claims (7)

In a mutual information exchange system for two-way CATV, in which a wired broadcasting station (A) and a plurality of subscriber stations (C) are connected to a common transmission path (B) to exchange information, the subscriber station (C) performs mutual transmission exchange. The first period of sending a request signal and the second period of sending a signal indicating that mutual information exchange is possible at the cable broadcasting station A are repeated, and the subscriber station prohibits the transmission of the signal during the first period. Interactive information exchange system for two-way CATV, characterized in that. The system of claim 1, wherein the cable broadcasting station (A) transmits a signal indicating that the mutual information cannot be exchanged with other subscribers during the second period. The mutual information exchange system for bidirectional CATV according to claim 1, wherein the cable broadcasting station A modulates and transmits data transmitted to each subscriber in one channel. The mutual information exchange system for two-way CATV according to claim 1, wherein the subscriber station (C) shares one channel to modulate data and transmit the data to the cable broadcasting station (A). The mutual information exchange system for two-way CATV according to claim 1, wherein each subscriber can share a peripheral device connected to a computer at the cable broadcasting station A. In claim 1, the subscriber station (C) stores its transmission data in a memory when the other subscriber and the cable broadcasting station (A) are in the process of information exchange, and immediately transmits the self transmission data after the information exchange with the other subscriber is completed. Interactive information exchange system for two-way CATV, characterized in that. The method of claim 6, wherein when a subscriber station (C) makes a request for information exchange with the cable broadcasting station (A), the information exchange request is made by pressing a channel selection switch without using a separate function switch. Interactive information exchange system for bidirectional CATV, characterized in that the signal is generated.

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