CN1212574A

CN1212574A - Measuring rod for uplink band in CATV transmission network

Info

Publication number: CN1212574A
Application number: CN98105572A
Authority: CN
Inventors: 金正旻
Original assignee: Korea Electric Power Data Network Co Ltd
Current assignee: Korea Electric Power Data Network Co Ltd
Priority date: 1997-09-20
Filing date: 1998-03-13
Publication date: 1999-03-31
Anticipated expiration: 2018-03-13
Also published as: JP2979539B2; KR100252305B1; CN1080066C; JPH11112959A; KR19990026023A

Abstract

The present invention relates to an incoming band measurement rod of a CATV transmission network, a connection piece is projected upward to a coupling bolt, to be coupled with a two-way coupler at one side and a bolt to be connected to a measurement device is formed integrally at the other side, a power supply separate section is configured in the inside of one side, at which the coupling bolt is formed to eliminate a power supply component included in a signal component, low-pass filter is connected to the power supply separate section to detect only a low-frequency signal from the signal from which the power supply component is eliminated, and noise included in the incoming signal sent from the subscriber to the CATV broadcast station is detected so that the outgoing signal sent from the CATV broadcast station to the subscriber is not interrupted and at the some time the test time can be shortened even with few inputs.

Description

The measurement column that in CATV transmission network, is used for uplink band

The present invention relates to send a kind of measurement column that is used for uplink band in the network at CATV (cable TV), more particularly, relate to a kind of like this measurement column that in CATV transmission network, is used for uplink band, occasion as the two-way catv business, even detect the upward signal that transmits from the user to the CATV broadcasting station and contain noise, it can avoid being sent to from the CATV broadcasting station interruption of user's downstream signal, and can further reduce the detection required time.

Usually known CATV business is to realize from a CATV broadcasting station to that the downlink broadcasting that divides other user sends and the two-way communication of the broadcast transmission of the up link from the user to this CATV broadcasting station.

The main method that adopts is, the downstream signal that sends to the user from the CATV broadcasting station is modulated onto on a HF signal that approximately is 54MHz, and is modulated onto big on a RF signal of 3-50MHz frequency band from the upward signal that user respectively sends to this CATV broadcasting station.

But the problem of initiation is to guarantee to avoid noise, because the easiest influence that is subjected to outside noise of 5-30MHz frequency band at the uplink signal place that sends from the user side to the CATV broadcasting station.

What adopt usually is the transmitting system that is used for CATV shown in Figure 1, wherein allow to provide the transmission of the two-way signaling between broadcasting station 1 and a plurality of user 9 of two-way services, shown system comprises a plurality of amplifiers 2 that are used to compensate up link between broadcasting station 1 and user 9 or down link signal decay, 3,4, the deconcentrator 5 that is used for the broadcast singal that sends to user 9 from said broadcasting station 1 is done separated time of a plurality of trees, 6,7, with a plurality of branch units 8 that are placed in the zone that described user yards up, be used for sending, make it to deliver to a plurality of independent users 9 from same separated time branch road for signal.

Amplifier

2,3,4 wherein need be installed within each location that is 600m to the maximum, decay to the degree of the enforcement of influence broadcasting so that prevent broadcast singal, and preferably this kind amplifier is installed, thereby the broadcasting service of good quality is provided at every 200m.Because majority is to adopt bidirectional coupler as

deconcentrator

5,6,7, it has the variable attenuation function of the relevant transmission range of response, and institute is so that all users can receive or the transmission signal with uniform quality.

But, utilize common CATV transmitting system, in the presence of when being included in noise in the uplink signal and measuring, in order to measure the noise that enters into branched line and deconcentrator, lineup person a measurement mechanism is connected to an amplifier and does under the situation situation of noise analysis, then another group personnel just one by one disconnect the reverse assembly that transmits signal to the user (other deconcentrator or branch unit) and measure.So, in the test section, the down link signal that sends from the broadcasting station not only is disconnected, and oppositely the measurement of the uplink signal on the parts is also impossible in for network in the uplink signal service conditions, and noise testing always needs two groups of personnel, cause the personnel of maintenance and repair of equipment and the increase on the cost, and need more time to be used for measuring the shortcoming of this common system that Here it is.

Particularly under the situation of doing to detect for the branched line of branch unit, after removing the branch unit module, testing process need be by a device detection line, so that the fault point of detection coaxial line is also measured the uplink signal in up transmission amplifier simultaneously, therefore need two ones and be used for the vehicle of aerial work and a large amount of man-hours; Under the situation of the operation circuit of testing a deconcentrator, beginning from first deconcentrator to remove these deconcentrator modules one by one in one of incoming terminal, performed test process is the measuring process that enters into the position of uplink signal at noise, therefore remove outside the interruption of the downlink broadcast signals during measuring, also need the vehicle of two aerial works and a large amount of man-hours.

So, the purpose of this invention is to provide a kind of measurement column that in CATV transmission network, is used for uplink band, when doing to detect for the noise that comprises the existing uplink signal that sends from the user to the CATV broadcasting station, can avoid the interruption of down link signal by a measurement column being inserted into the branch unit wanting measured or the simple operations of a deconcentrator, and then realize the saving of Measuring Time and manpower from the CATV broadcasting station to the user.

The realization of above-mentioned target is by adopting according to a measurement column that is used for the uplink signal frequency band in CATV transmission network of the present invention, it is included in a coupling bolt part on said measurement column one side, be used for being connected with a bidirectional coupler, said bolt partly utilizes a brace to protrude and forms, and bolt part is integrally formed in the other end with said post and is used for being connected with measurement mechanism, within the said inboard that comprises a coupling bolt, have the power supply separating part, be used for removing the power supply composition that is included in signal component, and said power supply separating part is received a low pass filter, so that from the signal that does not have the power supply composition, only detect the signal of low-frequency band, so that realize the detection that sends to noise the uplink signal of CATV from the user side for being included in, even if thereby realize using the artificial minimizing that Measuring Time also can be arranged that reduces, avoid sending to the interruption of user's down link signal simultaneously from the CATV broadcasting station.

Fig. 1 illustrates a system block diagram of the common transmitting system that is used for the two-way catv business of expression.

Fig. 2 illustrates the schematic diagram of formation of the present invention.

Fig. 3 illustrates the schematic diagram of detailed formation of the present invention.

Fig. 4 is the schematic diagram of user mode of the present invention.

One embodiment of the present of invention will be described in conjunction with the accompanying drawings.

Fig. 2 illustrates the formation of a measurement column according to an embodiment of the invention.

A measurement column 11 has a coupling bolt part 12 and bolt part of protruding formation at two ends, be used to send the signal that comprises the power supply composition.The coupling bolt part 12 that will be connected with a bidirectional coupler in the zone that will measure (deconcentrator among Fig. 1 and a branch unit) is protruded to be formed, have a brace 14 and a bolt part 13 at opposite side, be connected to the measurement mechanism of the existence that is used for definite noise.Inside at the measurement column 11 that forms said coupling bolt part 12 has a power supply separating part 15, so that remove the power supply composition that is included in the signal.As mentioned above, this power supply separating part 15 is received a low pass filter 16, so that make low band signal (the RF signal in the 5-30MHz frequency band) outside this signal, do not have the signal as up link of power supply composition detected, the measurement mechanism that is connected to this bolt part 13 comprising the existence of the noise in uplink signal detects.

Fig. 3 shows the detailed structure according to the measurement column of the embodiment of the invention, the brace 14 of a side of coupling bolt part 12 that wherein is positioned at the main body of measurement column 11 is received the power supply separating part 15 that comprises two capacitor C1, C2 and an inductance L 1, so that bypass is included in the power supply composition that enters into brace 14 in the signal.Walk by low pass filter 16 at the signal that does not have the power supply composition of power supply separating part 15, this low pass filter is by inductance L 2, L3, L4 and the L5 of series connection and capacitor C3, the C7 of aforementioned inductance upstream and downstream position, perhaps by inductance L 6, L7, L8 and the capacitor C 4 of connecting, C5, C6 ground connection, so that the RF signal only in frequency band 5-30MHz is as the upward signal that can be sent to the measurement mechanism that is installed in the accurate measurement that is used for noise on the bolt part 13.

As shown in Figure 1, by a plurality of

amplifier

2,3,4 from the broadcasting station 1 broadcast singal that sends by 5,6,7 separated times of a plurality of deconcentrators, and by a plurality of branch units 8 from same separated time lane assignment to other user 9 of branch.So,, still from the upward signal that divides other branch unit 8 to send to broadcasting station 1, comprise many noises through 1 broadcast singal as down link signal that sends to other user 9 of branch does not almost have noise from the broadcasting station.

So, as shown in Figure 4, when the coupling bolt part 12 on main body one side that is formed on measurement column 11 is received nut part 23 by screw thread identical, after a case type capping 22 of the outlet side of the

deconcentrator

5,6,7 that is in the bidirectional coupler form is laid down, send to various users' 9 signal through the input side 24 of this deconcentrator and through a plurality of output ports 21, or send to a side of broadcasting station 1 and can detect by brace 14 through the signal of internal distribution route from various users.

At power supply separating part 15, after from the signal that is sent to measurement column 11, removing the power supply composition, when the RF signal in the 5-30MHz scope that detects at low pass filter 16 has only the low-frequency band composition, uplink signal on 1 the direction from user 9 to the broadcasting station is sent to measurement mechanism, this measurement mechanism is received the bolt part 13 of measurement column 11, thereby can confirm to comprise noise.

On the other hand, as shown in Figure 1, when the main body of measurement column 11 is received one of output as the branch unit 8 of bidirectional coupler, or transmit and to send to each user's 9 signal by a plurality of outputs detected, or can be detected from the signal that divides other user 9 to send to broadcasting station 1 through this branch unit.

So, along with from being sent to the removal of the power supply composition the signal of the main body of the measurement column 11 of power supply separating part 15, when the RF signal in the 5-30MHz scope only is when the low-frequency band composition is detected, just can detect any noise that comprises, can both arrive measurement mechanism on the bolt part 13 that is installed in measurement column 11 subsequently because send to each of uplink signal of broadcasting station 1 from user 9.

As mentioned above, the measurement column that is used for the uplink band of CATV transmission network according to the present invention has such advantage, measure cylinder and have and protrude a coupling bolt part and bolt part that is formed on the opposite end, be used to send the signal that comprises the power supply composition; A coupling of the bidirectional coupler bolt part that will be connected in want measured zone is formed projectedly, has brace and bolt part at its opposite side, receives a measurement mechanism that is used for determining the noise existence; Inside in the main body that forms said coupling bolt part has a power supply separating part, so that remove the power supply composition that is included in the signal; And this power supply separating part is connected with a low pass filter, is contained in can accurately be detected as the noise in the low band signal of uplink signal outside the signal that does not comprise the power supply composition so that make.

And, when the part of the coupling bolt on the side in the measurement column main body is received a nut part by screw thread couple, after the seal cover of the closed type of output end of the deconcentrator that disassembles the bidirectional coupled form, just can detect the mutual signal that sends between output and input, and the power supply composition in this measurement column main body is removed at the power supply separating part of inside, and only the RF signal in the 5-30MHz scope is detected at low pass filter, thereby the advantage on effect is, by using the feasible measurement mechanism of being received the bolt part of measurement column main body, with respect to noise, the uplink signal of delivering to the broadcasting station from the user can be detected in simple mode.

Should understand that the embodiment of the invention described above is not for restriction of the present invention, and only is an example.

Specifically, the structure that should be noted that above-mentioned power supply separating part and low pass filter only be possible structure an example.

Claims

1. uplink signal frequency band measurement column that is used for sending at CATV network comprises:

Measure cylinder, be formed with a coupling bolt part and a bolt part at relative two ends projectedly, be used for making that the signal that comprises the power supply composition passes;

Coupling bolt part is connected to the bidirectional coupler that is formed with a brace of the protrusion in a tested zone; With

Power supply separating part and a low pass filter are configured in the inside of the said measurement cylinder that comprises said coupling bolt part, thereby make do not had the down link signal of power supply composition to be detected by the bolt part branch.

2. according to the measurement column of claim 1, the said power supply separating part of wherein receiving said brace in said measurement column comprises two capacitors and inductor, is used for the included power supply composition of signal that bypass enters through said brace.

3. measurement column according to claim 1, the low pass filter of wherein receiving the power supply separating part of measuring cylinder is configuration like this, make at the signal that does not have the power supply composition of said power supply separating part inductance by four series connection, and by described inductance upstream extremity and downstream end position electric capacity or capacitor that is connected and inductor formation branch road, thereby ground connection, thereby make the RF signal in the uplink signal 5-30MHz frequency band be sent to this bolt part.

4. measurement column according to claim 1, after being broken away from deconcentrator with as the closing cover of one of output of the branch unit of bidirectional coupler, the coupling bolt part in measurement column main body one side wherein is connected with this nut by screw thread couple.

5. measurement column according to claim 1 wherein has noise-measuring system to receive the bolt part of this measurement cylinder opposite side by screw thread couple, so that detect the existence of the noise in uplink signal.