JPH04216286A - Bidirectional catv device - Google Patents

Abstract

PURPOSE:To resolve data communication error due to ascending noise at an early stage and to improve transmission quality by inserting and installing an ascending noise detection circuit at a line, thereby easily defining the point of generating the ascending noise. CONSTITUTION:At the respective points of the CATV line, plural line amplifiers 10 are arranged with built-in ascending noise detection circuits 9 to detect the noise generated from terminal equipments. The ascending noise signal is passed through a high frequency amplifier, branched at a directional coupler 6 and inputted to the ascending noise detection circuit 9. The contents judged by the ascending noise detection circuit 9 are transmitted through the directional coupler 7 as data by a data signal transmitter 8. By applying an address function to the contents of the data transmitted from the line amplifier 10, the point of generating the ascending noise signal can be easily defined by an ascending data receiver provided at a center.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way CATV system equipped with a device for detecting upstream noise generated from terminal equipment.

0002

2. Description of the Related Art In recent years, in CATV systems, equipment having a two-way data communication function is increasingly required.

[0003] In a two-way CATV system, spurious components generated from electrical appliances used in each home where the terminal device is installed and spurious components that jump from the connector terminal of the amplifier are generated directly as noise or are transmitted to each branch. When the noise components from the road are synthesized and reach the data receiving device of the center facility mixed with the data signal, a problem occurs in that it interferes with data reception and makes it impossible to decipher the data.

0004

[Problem to be Solved by the Invention] In such conventional two-way CATV systems, upstream noise has a large effect on data reception at the center equipment, and in order to solve this problem, conventional gate control methods have been used to generate upstream noise. By cutting off the upstream transmission line at the point where the data is to be received, interference with data reception was eliminated and the transmission quality of the system was temporarily ensured. Not possible due to nature. Furthermore, as the scale of the system increases, more time and effort must be spent to identify the location where the problem occurs, and early resolution has been an issue.

[0005] The present invention solves the above problem, and aims to quickly solve data communication failures caused by upstream noise in a two-way CATV system by providing an upstream noise detection method.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a band-pass filter, a high-frequency amplifier, and a wave detector for capturing noise generated from electrical appliances used in each home. A bidirectional CATV system is configured in which line amplifiers equipped with determination circuits are appropriately inserted into bidirectional CATV lines.

[0007]

[Operation] According to the above-described configuration, the present invention can quickly eliminate interference with data reception due to upstream noise by inserting and installing an upstream noise detection device in a bidirectional CATV line, resulting in high-quality bidirectional CATV transmission. can be realized.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an upstream noise detection apparatus for implementing the upstream noise detection method of the present invention.

As shown in FIG. 1, it is comprised of a band pass filter 1 for passing noise signals, a high frequency amplifier 2 for amplifying the noise signals, a detector 3, and a comparison/judgment circuit 4. In the above configuration, the upstream noise signal (for example, 10 to 30 MHz band) extracted by the bandpass filter 1 is amplified to a predetermined level by the high frequency amplifier 2, detected by the detector 3, and sent to the comparison/determination circuit 4. This is used to detect the occurrence of upstream noise signals.

FIG. 2 shows the upstream noise detection device 9, second high-frequency amplifier 5, first directional coupler 6, second directional coupler 7, and data signal sending device 8 shown in FIG. 1 is a block diagram of a line amplifier 10 provided with the line amplifier 10. FIG.

In the above configuration, the upstream noise signal passes through the second high frequency amplifier 5, is branched at the directional coupler 6, and is input to the upstream noise detection circuit 9 shown in FIG. The content determined by the upstream noise detection circuit 9 is sent out as data by the data signal sending device 8 via the second directional coupler 7. However, the data signal is arranged, for example, in a 30-50 MHz band.

FIG. 3 is a block diagram of a bidirectional CATV system in which a plurality of line amplifiers 10 shown in FIG. 2 are appropriately arranged on a line.

In the above configuration, by giving the content of the data sent from the line amplifier 10 an address function, the upstream data receiving device 12 of the center equipment 11 can easily determine the location where the upstream noise signal is generated. can.

[0015]

As is clear from the above embodiments, according to the present invention, by using an uplink noise detection device in a two-way CATV system, it is possible to easily determine the location where uplink noise occurs. This enables early resolution of data communication failures and realizes a two-way CATV system with good transmission quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an uplink noise detection device showing an embodiment of the present invention.

[Figure 2] Block diagram of a line amplifier equipped with the upstream noise detection device shown in Figure 1

[Figure 3] Bidirectional CATV with line amplifier shown in Figure 2
Device block diagram

[Explanation of symbols]

1 Bandpass filter 2 High frequency amplifier 3 Detector 4 Comparison judgment circuit 5 High frequency amplifier 6,7 Directional coupler 8 Data signal sending device 9 Upstream noise detection device 10 Line amplifier 11 Center equipment 12 Upstream data receiving device

Claims (3)

[Claims] 1. A two-way CATV system comprising an upstream noise detection device for detecting upstream noise generated from a terminal device, and a line amplifier having a function of transmitting the generation status of the upstream noise as data. 2. The bidirectional CATV device according to claim 1, further comprising a line amplifier having a high frequency amplifier, a directional coupler, an uplink noise detection device, and a data signal transmission device. 3. An upstream noise detection device according to claim 1, comprising: a bandpass filter and a high frequency amplifier for capturing upstream noise generated from a terminal device; and a detector and a comparison circuit for detecting the upstream noise. Two-way CATV equipment.