JP2006005702A - Bidirectional catv system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CATV system capable of quickly specifying the occurrence of an abnormal state and its spot, recognizing the type and contents of the abnormal state that occurs, surely securing a service by narrowing a line area where communication or speech communication becomes impossible by turning off a gate switch circuit when the abnormal state occurs and preventing a subscriber who has not paid viewing fees and a subscriber who violates a contract from receiving television and interrupting streamed noise. <P>SOLUTION: A controller and a transmitter are installed at the center side of this CATV system, a gate controller is installed at an individual subscriber side, the gate controller is provided with a receiver for receiving a signal from the center and a transmitter, the controller manages the address of the gate controller and a state of a gate switch, and the gate controller makes the gate controller of an address corresponding to an address receive gate control information when the center transmitter transmits the gate control information for designating the address and makes the the transmitter of a gate controller responding to the control information send a notification signal to the center. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bidirectional CATV system capable of detecting an abnormality in a CATV system and preventing inflow noise from flowing into a center.

  The main line system of the current CATV system incorporates a gate switch circuit that cuts off the main line upstream system and protects center equipment when inflow noise occurs. Since the main line gate switch circuit is cut off for each main line system, if the line is cut off by the gate switch circuit, the cut-off line area becomes very wide.

  In the current CATV system, the abnormality cannot be automatically detected at the center, so when an abnormality occurs, the worker goes to a place that seems to be an abnormal part and communicates with the center to identify the abnormal place and the content of the abnormality. Check and repair the abnormality.

  Currently, communication services using the CATV interactive system include the Internet and IP telephone. If the line is interrupted as described above, in the Internet service, for example, if a home page is displayed, there is not much complaint from the subscriber, and if it recovers in the meantime, the customer is not aware of it. It may end up. However, in the IP telephone service, if the trunk gate is blocked, if there is a customer who is talking on the phone, the call is completely blocked, and a complaint that the subscriber cannot make a call is inundated. In this case, if the content of the call is important, complaints due to line disconnection become very large.

  The main causes of inflow noise are home appliances, short-wave radios, civilian radio bands, etc., and inflow noise generated from them jumps in from the point where the shield of the cable wiring is not perfect. When the subscription contract to CATV is determined, the incomplete portion of the subscriber's home wiring is usually repaired and completed before being connected to the subscriber. The same applies to apartment buildings. In an apartment house, the cable wiring to each home is usually connected continuously, but there are both subscribers and non-subscribers. In the case of subscribers, it is possible to renovate the wiring by entering the house, but it is currently difficult to renovate the wiring because it is usually difficult to get into a non-subscriber's house with permission. . For this reason, it is difficult to completely prevent inflow noise from an incomplete part of the wiring of a non-subscriber's house, and in the end, the situation is that it is troubled by countermeasures for inflow noise.

  Conventionally, when an abnormality occurs in the CATV line, it is troublesome for an operator to go to the vicinity of the abnormality site. In addition, since it is necessary to carry a communication transmitter with the center, a spectrum analyzer, a waveform observation measuring instrument, and the like to the site, it is labor intensive and difficult. Moreover, it takes time to find and check the abnormality, and it takes time to repair it. Furthermore, depending on the location where an abnormality has occurred, the line blocking area is widened, which inconveniences many subscribers who cannot receive. In some cases, complaints from subscribers may be inundated.

  The present invention can quickly identify the occurrence of CATV system anomaly and its site while staying at the center, and needs to bring out a communication transmitter, spectrum analyzer, waveform observation measuring instrument, etc. to confirm the abnormality. It is also possible to know the type and content of the abnormality that has occurred, and to ensure the service by narrowing the line area that is blocked by turning off the gate switch circuit at the time of abnormality and making communication and telephone calls as small as possible. There is to do. In addition, it is possible to stop the supply of downstream signals to subscribers who have not yet paid the viewing fee or to violate the contract so that they cannot receive the television, and to block inflow noise. Another object of the present invention is to provide a CATV system that can be used.

  In the CATV system of the present application, a controller and a transmitter are installed on the center side of the CATV system, a gate controller is installed on each subscriber side, and a receiver and a transmitter that receive signals from the center in the gate controller. The controller manages the gate controller address and the state of the gate switch, and when the gate controller sends addressed gate control information from the center transmitter, the control information is sent to the address corresponding to the address. The gate controller receives a notification signal from the transmitter of the gate controller responding to the control information. In this case, the gate controller can include two or more transmitters having different transmission frequencies. A waveform observation module can be installed in the gate controller. A downlink gate switch circuit is provided in each subscriber's downlink, and when the command signal from the center is received by the receiver of the gate controller, the downlink gate switch circuit is turned off and the supply of the downlink signal to the subscriber is stopped. I also made it possible. In this case, an upstream gate switch circuit that shuts off the upstream line is installed near the entrance of each CATV system in the apartment house or detached house, and when the indirect noise occurs, the upstream gate switch circuit is turned off to prevent the indirect noise. I tried to prevent the climb.

The CATV system of the present application has the following effects.
1. Since an upstream gate switch circuit is installed near the entrance of the CATV system in an apartment house or a detached house, the upstream line switch circuit is installed. It is possible to cope with this without stopping the service of the CATV system.
2. The current CATV TV service is charged, and it is a principle that communication should not be interrupted or stopped. In principle, if the service is interrupted or stopped, it can lead to a complaint of "Return money". There are many, and currently, labor costs and refunds corresponding to this are incurred. In the present invention, such complaints, labor costs, refunds, etc. can be minimized.
3. Normally, when a system trouble occurs, the maintenance staff will go to the site where the abnormality occurs and bring necessary equipment such as a transmitter for measurement and a waveform observation module, and send a transmission signal from the system terminal. Inserted into the upstream band and contacted with personnel at the center to check the level of arrival. In the present invention, since the transmitter for measurement and the waveform observation module are built in, it is possible to confirm and judge the abnormality only at the center side, and to reduce the labor cost and time required for it.
4). The problem with any cable TV station is how to deal with unpaid monthly fees. If there is an unpaid person, the cable TV station notifies the subscriber several times, and the construction staff goes to the unpaid person's house and continues to remove the lead-in line for the subscriber who is still unpaid. In the present invention, if the down gate switch circuit mounted on the down line (the position of each subscriber's protector) is turned off, the supply of the down signal to the subscriber can be stopped. By controlling the down gate switch circuit on the side, the signal supply to unpaid subscriber homes can be stopped so that they cannot receive television signals. For this reason, it is possible to perform the wave stopping process for the unpaid subscribers without going to the construction site, thereby reducing the labor cost.

(Embodiment 1)
The CATV system of the present invention will be described with reference to FIGS. In the CATV center of FIG. 1, a transmitter (transmitter / receiver) 1 including a controller, a control personal computer (PC) 2 for controlling the transmitter, and a head end (HE) 3 are installed, and a gate controller 4 is installed at the terminal. is set up. As shown in FIG. 2, the controller 1 is connected to the PC via the I / O, and the downstream RF signal is output through the transmitter 6 and the upstream RF signal is input through the receiver 7.

  As shown in FIG. 3, the gate controller 4 is built in or externally attached to a bi-directional amplifier installed near (terminal) each individual subscriber. The bidirectional amplifier includes a downstream signal system path 10 and an upstream signal system path 20, and the downstream signal system path 10 includes a downstream signal input adjuster 11, an amplifier 12, a downstream signal gain controller (GC) 13, and a downstream gate switch circuit 14. , And an upstream signal input path 21, an upstream gate switch circuit 22, an amplifier 23, an upstream signal gain regulator (GC) 24, and an amplifier 25. The gate controller 4 includes a receiver 41, two transmitters 42 and 43 having different transmission frequencies, and a waveform observation module 44.

The operation of the CATV system of the present invention will be described with reference to FIGS. The bidirectional amplifier and gate controller 4 shown in FIG. 1 operates by supplying a necessary voltage from a stable power supply (AVR) 8. The operation of the bidirectional amplifier is the same as that of the existing bidirectional amplifier.
The control signals from the controller and transmitter 1 in FIG. 1 are mixed by the downstream mixer of the head end (HE) 3 in FIG. 1 and sent to the trunk line together with the downstream signal (TV / data signal) and installed on the subscriber side. Input to a bidirectional amplifier. The center detects inflow noise, and if there are many, the upstream gate switch circuit 22 of the upstream signal path 20 of the bidirectional amplifier is turned off to block the flow of inflow noise to the center.

  The gate controller 4 installed in the terminal is controlled by operating the center controller 1. The controller 1 manages the address of the gate controller 4 and the states of the upstream and downstream gate switch circuits 14 and 22 and sends the gate control information to the gate controller 4 to which the address designated by the operator is assigned. The transmitted gate control information is transmitted to the receivers 41 of all gate controllers 4 installed in the CATV system, where the address of the gate control information is compared with the address set for each gate controller 4. When both addresses match, the transmitters 42 and 43 of the matched gate controller 4 transmit / stop based on the command from the controller 1 at the center. For example, when a trouble occurs in the uplink system, the center controller 1 controls the transmitters 42 and 43 to transmit and confirms the frequency on the center side to analyze the trouble of the CATV system. Can do. For example, the transmission frequency of one transmitter 42 is 10 MHz (upstream lower limit frequency), and the other transmitter 43 is 55 MHz (upstream upper limit frequency). If there is an abnormality in the balance (tilt characteristics) or attainment level of two frequencies, it is determined that there is an abnormality in equipment or cables / connectors installed in the middle of the CATV system. Can do. In this case, there is no need to bring a transmitter to the site.

  By observing the waveform displayed on the waveform observing module 44 mounted on the gate controller 4 together with the abnormality detection at the transmitter, it is possible to make a finer judgment while staying at the center. In this case, it is not necessary to bring a spectrum analyzer or a waveform observation measuring instrument or the like to the site as in the prior art.

  Further, when the downstream signal gate switch circuit 14 mounted on the downstream path 20 is turned off based on a command from the center, the downstream signal sent from the center is cut off and is not supplied to the subscriber. You can prevent it from being seen.

  There may be one transmitter or three or more transmitter frequencies. If the number of transmitters increases, the content and type of abnormality can be confirmed in detail. The transmission frequency can also be set according to the application.

  The control PC shown in FIG. 1 is a personal computer different from the controller-dedicated personal computer 2 and is installed inside the center or outside the center but inside the center, or constitutes an in-house LAN. By operating the control PC, the controller-dedicated personal computer 2 can be operated to operate the controller / transmitter 1. In addition to the control PC shown in FIG. 1, the controller-dedicated personal computer 2 can be operated by a personal computer outside the center via the Internet, and the controller / transmitter 1 can be operated.

1 is an overall view of a CATV system. Explanatory drawing of the controller and transmission part of the CATV center side. Explanatory drawing of a gate control machine.

Explanation of symbols

1 Transmitter (Transceiver)
2 Control PC (PC)
3 Headend (HE)
4 Gate controller 6 Transmitter 7 Receiver

Claims (5)

  A controller and transmitter are installed on the center side of the CATV system, a gate controller is installed on each subscriber side, a receiver and a transmitter that receive signals from the center are installed on the gate controller, and the controller controls the gate. The gate controller manages the machine address and the state of the gate switch, and when the gate control information for addressing is sent from the center transmitter, the gate controller of the address corresponding to the address receives the control information, A bidirectional CATV system characterized in that a notification signal from a transmitter of a gate controller responding to the control information is sent to the center.   2. The bidirectional CATV system according to claim 1, wherein the gate controller comprises two or more transmitters having different transmission frequencies.   3. The bidirectional CATV system according to claim 1 or 2, wherein the waveform controller is provided in the gate controller.   4. A bidirectional CATV system according to claim 1, wherein a downlink gate switch is provided in the downlink of each subscriber, and a command signal from the center is received by a receiver of the gate controller. When receiving, the bidirectional CATV system is characterized in that the downstream gate switch circuit is turned off to stop the supply of the downstream signal to the subscriber. 5. The bidirectional CATV system according to claim 1, wherein an upstream gate switch for interrupting an upstream line is installed near each CATV system entrance of an apartment house or a detached house to generate inflow noise. A bidirectional CATV system characterized in that the switch circuit is sometimes turned off to prevent upstream inflow noise.

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