KR100866594B1 - Multi-cell monitering apparatus of hfc network - Google Patents

Abstract

HFC network multi upward cell monitoring apparatus is provided to simplify cabling work and minimize the installation space by combining a demodulator and a spectrum analyzer. An NMS server(2) controls entire system and transmits downward broadcasting signal and downward control instruction signal to the network. A modulator(5) modulates signal output from the NMS server to FSK (frequency Shift Keying). A combiner(6) combine modulated various kinds of downward signal and transmits each unit cell of the network. A distributor(7) receives the upward signal of each of the upward cells transmitted from the network and distributes it to the corresponding apparatus.

Description

HFC network multi up cell monitoring device {MULTI-CELL MONITERING APPARATUS OF HFC NETWORK}

According to the present invention, equipment installed in each cell of an HFC (optical coaxial mixed network) network (including a CATV network), which is a transmission network for transmitting data such as Internet service, Internet telephony, analog and digital broadcasting, is used as a headend (national). The present invention relates to an HFC network multi uplink cell monitoring apparatus for real-time monitoring of uplink status data to be transmitted and managing HFC network efficiently based on this, thereby stably supplying high quality service.

In general, HFC networks (including CATV networks) are a mixture of fiber optic cables and coaxial cables that combine fiber and coaxial cables in different parts of the network to transport data such as video, voice, and files. It is a communication technology to be used, which combines the advantages of fiber optic cable and coaxial cable to overcome the limitations of transmission speed and bandwidth, and has excellent bi-directional characteristics, low maintenance cost and low installation cost.

The HFC network (hereinafter referred to as 'network') divides the broadcasting area managed by the headend (national company) into several unit cell areas, uses fiber optic cables from the headend to the unit cell, and the unit cell to each subscriber. Coaxial cable is used.

In the HFC network, equipment such as an optical transceiver (ONU), a trunk branch amplifier (TBA), and a power supply (PS, UPS) is installed.

The optical transceiver transmits and receives various data with the headend through the optical cable, the trunk branch amplifier amplifies the level of the signal degraded due to coaxial cable loss and transmits it to the subscriber or another trunk branch amplifier, the power supply is the optical Supply driving power to transceiver and trunk branch amplifier. That is, in general, one optical transceiver, a plurality of trunk branch amplifiers, and a plurality of power supplies are connected in a topology (tree or ring structure) in one unit cell area to transmit data transmitted from the headend to each subscriber. do.

In general, a signal transmitted from a headend toward a subscriber (unit cell) is called a downlink (RF) signal, and a signal transmitted from a subscriber toward the headend is called an uplink signal.

In general, the downlink signal refers to various broadcast signals (audio, video, etc.) provided to the subscriber by the headend. Of course, the control signal emitted by the headend to control various equipment installed on the track of the network is also a downlink signal.

This downlink broadcast signal is transmitted at high quality at the headend, but if there is a network problem, each subscriber is not provided with high quality broadcast data. Therefore, the headend is obliged to provide a high quality service to the subscriber by monitoring the network status from time to time to solve the problem immediately.

Problems that occur in the network that degrades the quality of serviced broadcast data are mainly when equipment installed in the network is not working properly or noise is introduced at some point of the network line. In particular, when noise is introduced, the noise affects not only the corresponding cell but also other cells, and therefore, a quick measure is required.

In this way, the devices installed in the network (ONU, TBA, PS, etc.) in order to maintain the network in an optimal state by monitoring (monitoring) the factors of the network that degrades the quality of the downlink broadcasting data in real time are the status data of the equipment itself. (E.g. input / output voltage and current, Rx power, Tx power, enclosure temperature of equipment, flooded condition of enclosure, opening / closing of enclosure door) and status data of downlink signal (e.g. SNR, MER, BER, RF POWER, Transponders are installed to extract the EVM and transmit them to the upstream headend, and the headend analyzes the status data transmitted by the transponder of each device to monitor the status of the corresponding equipment or the status of the downlink broadcast signal.

A device that detects the state of the network by receiving various state data transmitted by the equipment installed in the network, and a demodulator that receives and demodulates the state data of the equipment itself installed in the network, and analyzes the state data of the downlink broadcast signal in the form of spectrum I have a spectrum analyzer

In the prior art, since the demodulator and the spectrum analyzer are installed in the headend as independent equipment, one demodulator and the spectrum analyzer receive and process the state data from a certain number of cells (usually 8 cells). Demodulator and spectrum analyzer are installed.

As a result, the headend must have a large space for installing a large number of demodulators and spectrum analyzers, and the cabling work for electrically connecting these and other devices is complicated.

In addition, the conventional spectrum analyzer does not analyze broadcast signal state data transmitted from a predetermined number of cells, but analyzes broadcast signal state data by receiving broadcast signal state data for each unit cell.

To this end, the prior art requires a selector that connects a cell and a spectrum analyzer one-to-one by the number of cells, and it takes a lot of time to analyze the broadcast signal state data of each cell.

The present invention has been made to solve the above problems, by combining the demodulator and spectrum analyzer into a single device rather than a separate separate equipment to minimize the installation space and simplify the cabling work,

The purpose of the present invention is to provide a multi-upstream cell monitoring device having high efficiency while reducing analysis time of broadcast signal state data by including a cell switch capable of connecting a cell (state data transmitted from a cell) and a spectrum analyzer in one-to-one as well as many-to-one. It is done.

HFC network multi uplink cell monitoring apparatus of the present invention for achieving the above object

An input unit for receiving various upstream state data transmitted by equipment installed in a plurality of cells of an HFC network through a distributor;

A first combiner for combining the state data of the devices among various state data of the plurality of cells received by the input unit;

An FSK demodulator for demodulating the device's own state data of cells coupled in the first combiner according to a frequency shift modulation method;

A second combiner for combining the state data of the downlink signal sensed by the equipment among various state data of the plurality of cells received by the input unit;

An upstream data processing unit including a spectrum analyzer configured to analyze broadcast signal state data of cells coupled in the second combiner in a spectral form through A / D converting;

A UI unit including a display unit for displaying the processed state data in numerical and spectral form through the FSK demodulator and the spectrum analyzer, and a keyboard for manipulating the matters to be displayed on the display unit;

And a central control unit which transmits various state data transmitted from the processing unit to the UI unit and is connected to a peripheral device to transmit and receive various signals.

And the processing unit

And a cell switch which blocks transmission of broadcast signal state data of one cell selected from among broadcast signal state data of a plurality of cells transmitted from the input unit to a second combiner or broadcast signal state data of some cells.

The central control unit receives the state data from a plurality of the processing unit,

And a multiplexer for multiplexing the state data transmitted by the FSK demodulator of each of the plurality of processing units and transmitting the multiplexed state data to the central control unit.

The UI unit

And comparing and comparing the state data processed and transmitted through the FSK demodulator and the spectrum analyzer with a pre-stored reference value to analyze whether there is an abnormality.

The FSK demodulator

A first low pass filter (LPF) for filtering the low band of the input state data signal;

A demodulation unit for mixing the state data signal passing through the first low pass filter with the oscillation frequency of the oscillation unit and demodulating the signal into a specific frequency band;

A first controller which transmits the state data signal transmitted by the demodulator to the central controller, and controls the oscillation frequency of the oscillator;

A first attenuator and a first amplifier connected in series between the first low pass filter and the demodulator, and stably demodulating the demodulator by adjusting the strength of the state data signal input from the first low pass filter; Characterized in that consisting of,

The spectrum analyzer is

A second low pass filter (LPF) for filtering the low band of the input state data signal;

An A / D converter for converting the analog state data signal passing through the second low pass filter into digital state data according to the sampling frequency of the oscillator;

A second controller which transmits the state data signal transmitted from the A / D converter to the central controller, and controls a sampling frequency of the oscillator;

A buffer (FIFO) for temporarily storing the output state data of the A / D converter and transmitting it to the second controller;

A second connection between the second low pass filter and the A / D converter, the second low pass filter controlling the intensity of the state data signal input from the second low pass filter so as to stably convert the A / D converter Characterized in that it comprises an attenuator and a second amplifier,

The multiplexer

An input controller for receiving state data from the FSK demodulator of each of the plurality of processing units, and detecting an error of the inputted demodulated state data;

An FPGA for temporarily storing and transmitting state data transmitted by the input controller;

And an output controller for receiving the state data of the selected cell according to a predetermined program from the FPGA and outputting the state data to the central controller.

The comparative analysis unit of the UI unit analyzes the state data processed and transmitted through the FSK demodulator and the spectrum analyzer, respectively, and includes a demodulator comparison analysis unit and a spectrum comparison analysis unit connected to the display unit,

The UI unit

A receiver for receiving the broadcast signal state data of the spectrum analyzer and the equipment itself state data of the FSK demodulator from the central controller;

The keyboard is connected, and further comprising a microcomputer to recognize the type of state data transmitted by the receiving unit and to distribute it to the corresponding spectrum comparator or demodulator comparator.

According to the present invention having the configuration as described above, the FSK demodulator and the spectrum analyzer are combined into one and can receive and process state data from more cells, thereby minimizing installation space for them, simplifying cabling work, and monitoring HFC room. Improve efficiency

In addition, only the broadcast signal state data of one cell may be transmitted to the spectrum analyzer through the cell switch, or the broadcast signal state data of multiple cells may be simultaneously transmitted, thereby reducing the analysis time of the downlink signal state data and increasing efficiency. Therefore, the tracking of the noise inflow contact accordingly can also be performed quickly.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

1 is a schematic block diagram of an HFC network monitoring / management system of a headend installed with a multi uplink cell monitoring apparatus according to the present invention.

As shown in FIG. 1, an NMS server 2 which transmits a downlink broadcast signal and a downlink control command signal to a network and controls the system as a whole,

A modulator 5 for modulating a frequency output modulation (FSK) signal output from the NMS server;

A combiner 6 for combining the modulated various downlink signals and sending them to each unit cell of the network;

There is a distributor 7 which receives an uplink signal of each uplink cell transmitted from a network and distributes it to a corresponding device.

There is a multi uplink cell monitoring apparatus 1 of the present invention for monitoring and analyzing the state of a network from various state data transmitted by the distributor.

The NMS server and the monitoring device of the present invention are electrically connected to each other to transmit and receive various signals, and these are connected to the SMS server 4 and the client 3 through Ethernet to transmit and receive various signals.

If there is a problem with the system or the network problem, the SMS server sends a problem message to a mobile phone which is registered in advance to notify the administrator promptly.

And even if the administrator is not at the headend, the client can connect to the system wherever it is available and check the status of the system and network, and control them.

2 is a schematic configuration diagram of a multi uplink cell monitoring apparatus according to the present invention.

As shown in the figure, the monitoring device of the present invention is the USB processing unit 100, the UI unit 40, the central control unit 30, USB 10 for relaying the data transmission of the processing unit 100 and the central control unit 30 And a multiplexer 20 and a power supply unit 50 for supplying power.

The processing unit 100 is composed of an electronic device mounted on a slot board, and receives the state data from eight cells. The central control unit 30 receives the processed state data from the plurality of processing units 100.

The central control unit 30 controls the monitoring apparatus of the present invention as a whole, and is connected to the SMS server and the client via the NMS server and the Ethernet through the server block 60, and is provided on the outer surface of the case of the monitoring apparatus. It controls the operation of the alarm means 70, such as a speaker, and informs whether the upstream signal is normally received from each cell or whether there is a problem in the network.

The central control unit 30 may receive state data from one processing unit 100, or may receive state data from various processing units 100.

3 is a block diagram of the processing unit 100, and as shown in the drawing, the processing unit 100 includes an input unit 160, a first combiner 140, a second combiner 150, and a cell switch ( 130), including the FSK demodulator 110 and the spectrum analyzer 120, these are mounted on a single PCB slot board.

The input unit 160 receives various state data upward from equipment installed in each cell of the network. The present invention is configured such that eight cells of the network are connected to one processing unit 100, the input unit 160.

The first combiner 140 combines the state data of the equipment itself, which is installed by the equipment installed in the network among the state data of the cells input to the input unit 160 and transmits it to the FSK demodulator 110.

Here, the state data of the equipment itself is common state data extracted by each equipment such as input / output voltage and current, Rx power, Tx power, enclosure temperature of the equipment, flooded state of the enclosure, opening or closing of the enclosure door,

In case of ONU, state data such as OTX leisure diode current value, OTX power, ORX (optical receiver) power is further extracted.

In the case of UPS (uninterruptible power supply), further extracts the status data such as whether there is commercial power input, commercial power input voltage and input current, battery voltage, inverter operating status, test and reset normal operation,

In the case of APS (Power Switcher), it further extracts status data such as voltage and current input from PS (Power Supply), presence of PS failure and short circuit in transmission network. The state data extraction method of these equipments themselves will also be known technology, so a detailed description thereof will be omitted.

The second combiner 150 combines the state data of the downlink broadcast signal among the state data of the cells input to the input unit 160 and transmits the state data to the spectrum analyzer 120.

Here, the state data of the downlink signal includes SNR, MER, BER, RF POWER, EVM, and the like. Since a method of extracting these values is a known technique, a detailed description thereof will be omitted.

The cell switch 130 blocks transmission of state data of any cell among the state data of the broadcast signal of each cell transmitted from the input unit 160 to the second combiner 150.

The cell switch 130 may block each cell individually or simultaneously block several cells of any selected combination. In addition, the administrator may block by manual operation, or may be automatically blocked depending on the program.

Normally, the state data of the broadcast signals input from 8 cells are combined and transmitted, and the state of the broadcast signals of 8 cells is displayed in one spectrum to monitor the state. When generated, the cell switch 130 sequentially or automatically blocks transmission of broadcast signal state data of a cell (each cell or a combination of cells) through the cell switch 130 to find a cell into which noise is introduced.

The cell switch 130 may block the state data of the equipment itself of the cells transmitted to the first combiner 140 as well as the second combiner 150.

The FSK demodulator 110 demodulates state data of each cell input through the first combiner 140, and the spectrum analyzer 120 spectra the state data of each cell input through the second combiner 150. Processed to be displayed in form.

As shown in FIG. 4, the FSK demodulator 110 includes a first low pass filter 111, a demodulator 114, a first controller 115, a first attenuator 112, and an amplifier.

The first low pass filter 111 (LPF) filters the low band of the input state data signal,

The state data signal passing through the first low pass filter 111 is adjusted to a level capable of stably demodulating the demodulator 114 by passing through the first attenuator 112 and the first amplifier 113. In other words, if the strength of the signal is too large or too small, demodulation may not be performed normally. Therefore, a signal whose strength is weak or large among the state data signals is raised or lowered to an appropriate level.

The demodulator 114 demodulates the state data passing through the first attenuator 112 and the first amplifier 113 with the oscillation frequency of the oscillator to a specific frequency band.

The demodulator 114 modulates data using a frequency shift keying (FSK) method, which is a frequency shift modulation method. Frequency shift modulation is one of the digital modulation methods that use frequency. The reason for using digital modulation method for data modulation is that the transmission of digital signals is relatively more efficient than the transmission of analog signals. In terms of aspects, it is much more advantageous than sending the data as an analog modulation scheme, and in particular, the frequency modulation scheme is relatively simple and inexpensive.

The first controller 115 transmits the demodulated state data through the demodulator 114 to the UI unit 40 through the multiplexer 20 and the central controller 30, and transmits the oscillation frequency of the oscillator 116. The RF reception sensitivity of the uplink signal transmitted from each cell is measured through the input state data.

As shown in FIG. 5, the spectrum analyzer 120 includes a second low pass filter 121, an A / D converter 124, a second controller 125, a buffer 127, a second attenuator 122, and a second attenuator 122. It consists of two amplifiers (123).

The second low pass filter 121 (LPF) filters the low band of the input state data signal.

The second attenuator 122 and the second amplifier 123, like the first attenuator 112 and the second amplifier 123, determine the strength of the state data signal of the broadcast signal passing through the second low pass filter 121. Adjust to an appropriate level.

The A / D converter 124 samples the analog state data signal input according to the sampling frequency of the oscillator 126 and converts the state data signal into digital state data at high speed.

The buffer 127 temporarily stores the output state data of the A / D converter 124 and transmits the data to the second controller 125. The buffer 127 sequentially outputs state data input as a first in first out (FIFO).

The second controller 125 transmits the state data input from the buffer 127 to the UI unit 40 via the USB 10 and the central controller 30, and controls the sampling frequency of the oscillator 126. do. In addition, a control command is issued to the cell switch 130 to control the operation of the cell switch 130. The memory 128 connected to the second controller 125 includes data necessary for setting the sampling frequency of the oscillator 126, data necessary for controlling the cell switch 130, and A / D converted cells. Save the state data.

FIG. 6 shows a block diagram of the multiplexer 20, which includes an input controller 21, an FPGA 22 (Field Programmable Gate Array), and an output controller 23, as shown in the figure.

The multiplexer 20 multiplexes the state data of the FSK demodulator 110 transmitted from the plurality of processing units 100 to the central control unit 30. In the present invention, one multiplexer 20 can process the state data transmitted from the eight processing units (100).

The input controller 21 receives processed state data from various FSK demodulators 110, detects whether there is a demodulation error in the input state data, and sum checks them. And the input controller 21 is connected to the communication port for RS-232 communication.

The FPGA 22 temporarily stores the state data transmitted from the input controller 21 and transmits the state data to the output controller 23. In addition, the memory connected to the FPGA 22 stores additional information about a reception sensitivity reference value of the state data for determining whether the output is determined, a version of the multiplexer, and the like.

The output controller 23 receives a predetermined program or state data of a cell selected by the central controller 30 in response to a request from the FPGA 22 and transmits the state data of the selected cell to the UI unit 40 through the central controller 30. .

7 is a block diagram of the UI unit 40, and includes a receiver 41, a microcomputer 42, a keyboard 46, a comparison analyzer 43, 44, and a display 45. As shown in FIG.

The receiver 41 receives various state data processed through the central controller 30.

The microcomputer 42 recognizes (identifies) whether the input state data is the state data of the device itself or the state data of the broadcast signal, and transmits the same to the corresponding spectrum comparison analyzer 44 or the demodulator comparison analyzer 43. do. In addition, this is provided to the NMS server and the client through the central control unit 30.

The display unit 45 shows the state data in numerical and spectral form for the administrator to see, and the keyboard 46 is for the operation of the administrator, and the manager is displayed on the display unit 45 through the keyboard 46. Display mode of data, items, and status data, selection of cells to be displayed, transmission of status data to other devices, setting of reference values for determining whether there is abnormal status data, and a network through the central controller 30. The down control signal can be emitted.

Spectrum comparison analysis unit 44 of the comparison analysis unit receives the state data of the broadcast signal, verifies the validity of the received state data, and in the state data various data (SNR, MER, BER, RF POWER, EVM, etc.) ) And then compare it with the reference value to determine if there is a move, and then compare and quantify the noise level with the reference value.

The demodulator comparison analysis unit 43 of the comparison analysis unit receives the state data of the equipment itself, verifies the validity of the received state data, and in the state data various data (voltage and current, Rx power, Tx power, equipment of After extracting the enclosure temperature, the submerged state of the enclosure, whether the enclosure door is opened or closed, etc., it is compared with the reference value to determine the abnormality.

In the above description of the present invention has been described with respect to the HFC network multi up-cell monitoring apparatus having a specific function and configuration with reference to the accompanying drawings, the present invention can be variously modified and changed by those skilled in the art, such variations and modifications It should be interpreted as falling within the protection scope of the present invention.

1 is a schematic overall block diagram of an HFC network monitoring and management system of a headend in which the present invention is installed.

2 is a schematic block diagram of a multi uplink cell monitoring apparatus according to the present invention;

3 is a schematic block diagram of a processing unit;

4 is a schematic block diagram of an FSK demodulator.

5 is a schematic block diagram of a spectrum analyzer.

6 is a schematic block diagram of a multiplexer.

7 is a schematic block diagram of a UI unit.

<Description of the symbols for the main parts of the drawings>

10: USB 20: Multiplexer

30: central control unit 40: UI unit

100: processing part 110: FSK demodulator

120: spectrum analyzer 130: cell switch

140: first coupler 150: second coupler

Claims (8)

An input unit for receiving various upstream state data transmitted by equipment installed in a plurality of cells of an HFC network through a distributor; A first combiner for combining the state data of the devices among various state data of the plurality of cells received by the input unit; An FSK demodulator for demodulating the device's own state data of cells coupled in the first combiner according to a frequency shift modulation method; A second combiner for combining the state data of the downlink signal sensed by the equipment among various state data of the plurality of cells received by the input unit; An upstream data processing unit including a spectrum analyzer configured to analyze broadcast signal state data of cells coupled in the second combiner in a spectral form through A / D converting; A UI unit including a display unit for displaying the processed state data in numerical and spectral form through the FSK demodulator and the spectrum analyzer, and a keyboard for manipulating the matters to be displayed on the display unit; And a central control unit for transmitting various state data transmitted from the processing unit to the UI unit and transmitting and receiving various signals connected to a peripheral device. The method of claim 1, wherein the processing unit HFC further comprises a cell switch to block the transmission of the broadcast signal state data of any one cell selected from among the broadcast signal state data of a plurality of cells transmitted from the input to the second combiner Network multi up cell monitoring device. The method of claim 1, The central control unit receives the state data from a plurality of the processing unit, And a multiplexer for multiplexing the state data transmitted by the FSK demodulators of each of the plurality of processing units and transmitting the multiplexed state data to the central control unit. According to any one of claims 1 to 3, wherein the UI unit HFC network multi up-cell monitoring apparatus further comprises a comparison analysis unit for analyzing the presence of abnormality by comparing the state data processed and transmitted through the FSK demodulator and the spectrum analyzer previously stored. The method according to any one of claims 1 to 3, wherein the FSK demodulator A first low pass filter (LPF) for filtering the low band of the input state data signal; A demodulation unit for mixing the state data signal passing through the first low pass filter with the oscillation frequency of the oscillation unit and demodulating the signal into a specific frequency band; A first controller which transmits the state data signal transmitted by the demodulator to the central controller, and controls the oscillation frequency of the oscillator; A first attenuator and a first amplifier connected in series between the first low pass filter and the demodulator, and stably demodulating the demodulator by adjusting the strength of the state data signal input from the first low pass filter; HFC network multi up-cell monitoring apparatus comprising a. The method according to any one of claims 1 to 3, wherein the spectrum analyzer A second low pass filter (LPF) for filtering the low band of the input state data signal; An A / D converter for converting the analog state data signal passing through the second low pass filter into digital state data according to the sampling frequency of the oscillator; A second controller which transmits the state data signal transmitted from the A / D converter to the central controller, and controls a sampling frequency of the oscillator; A buffer (FIFO) for temporarily storing the output state data of the A / D converter and transmitting it to the second controller; A second connection between the second low pass filter and the A / D converter, the second low pass filter controlling the intensity of the state data signal input from the right pass filter so that the A / D converter can be stably converted; HFC network multi up-cell monitoring apparatus comprising a second attenuator and a second amplifier. 4. The multiplexer of claim 3 wherein the multiplexer An input controller for receiving state data from the FSK demodulator of each of the plurality of processing units, and detecting an error of the inputted demodulated state data; An FPGA for temporarily storing and transmitting state data transmitted by the input controller; And an output controller for receiving the state data of a cell selected according to a predetermined program from the FPGA and outputting the state data to the central controller. The method of claim 4, wherein The comparison analysis unit of the UI unit analyzes the state data processed and transmitted through the FSK demodulator and the spectrum analyzer, respectively, and includes a demodulator comparison analysis unit and a spectrum comparison analysis unit connected to the display unit, The UI unit A receiver for receiving the broadcast signal state data of the spectrum analyzer and the equipment itself state data of the FSK demodulator from the central controller; The keyboard is connected, the HFC network multi up-cell monitoring characterized in that it further comprises a microcomputer to recognize the type of state data transmitted by the receiving unit to distribute it to the corresponding spectrum comparator or demodulator comparator Device.

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