JPH0653865A - Method for constructing communication line - Google Patents

Abstract

PURPOSE:To construct a communication line without stopping the transmission of a signal and to suppress the deterioration time of transmission quality to its minimum. CONSTITUTION:In the case of constructing a line 2 for cascade-connecting a line amplifier 1, a stand-by terminal 5 different from a line connecting terminal 4 connected to the line 2 out of two line amplifiers 1 arranged on both sides of an instruction place 3 is connected to a by-pass 7 connected to an auxiliary amplifier 6 to connect both amplifiers 1. Then the line 2 between both amplifiers 1 is disconnected from the terminal 4, the by-pass line 7 connected to the stand-by terminals connected to respective amplifiers 1 is switched and connected to the terminals 4 of respective amplifiers 1 by respective switches 8 to connect between both amplifiers 1, and in the state, construction is executed in the place 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing various lines such as a coaxial cable, a pair line, and an optical fiber in which a plurality of amplifiers are cascade-connected, and particularly CA
It is suitable for line work such as relay transmission line or telephone line in a TV system in which signal transmission cannot be stopped even during construction.

[0002]

2. Description of the Related Art As described above, in the construction of a coaxial cable, a pair wire, an optical fiber or the like provided with an amplifier, a construction method as shown in FIGS. Was there. First, in the construction method of FIG. 3, the line A in the construction section is separated from the line connection terminals C of the amplifiers B on both sides of the line A, the signal transmission to the line A is stopped, and the line A is constructed in this state. After the line construction is completed, the line A is connected to the line connection terminal C of the amplifier B to restart the signal transmission and the construction is completed.

Further, the construction method shown in FIG. 4 is designed so that line construction can be performed without stopping transmission.
Before disconnecting the line A in the construction section from the line connecting terminal C of the amplifier (line amplifier) B, the bypass line F in which the auxiliary amplifier E is connected to the spare terminal D of both line amplifiers B
To connect between the amplifiers B for both lines, and then disconnect the line A from the line connecting terminal C of each line amplifier B, perform line construction in this state, and connect the line A again after the construction is completed. The work is completed by connecting the amplifier B for use.

Since the spare terminal D provided in the ordinary line amplifier B has a different specification from the line connecting terminal C and is not intended for line connection, the output level of each line amplifier B is The frequency characteristic deviation or the like is output without being corrected. The auxiliary amplifier E provided on the bypass line F is for roughly performing such correction.

[0005]

However, the above construction method has the following problems. According to the construction method of FIG. 3, signal transmission is stopped during construction, so that communication service is deteriorated. If the construction period is long, the effect will be significant. In the construction method of FIG. 4, signal transmission does not stop even during the line construction, but the spare terminal D is not intended for line connection, so the output from the terminal D has no specification value. Therefore, the characteristics differ for each line connection amplifier B. Therefore, the auxiliary amplifier E only assists the minimum characteristic common to the outputs from all the spare terminals D. Therefore, the signal output from the spare terminal D is sent to the spare terminal D of the other line amplifier B without being sufficiently corrected. Therefore, compared with the signal output from the line connecting terminal C after being amplified by the line amplifier B, the signal quality of the signal of the bypass line F is impaired due to frequency characteristic deviation, distortion, etc., and deterioration of image quality during construction is avoided. I couldn't do it.
In particular, it is difficult to correct the distortion during analog transmission, and the deterioration of transmission quality becomes remarkable.

An object of the present invention is to provide a method for constructing a line which makes it possible to minimize the time during which the transmission quality deteriorates without stopping the transmission of signals during the line construction.

[0007]

As shown in FIG. 1, a line construction method of the present invention is a line such as a coaxial cable, a pair line, an optical fiber, etc. in which at least two or more line amplifiers 1 are cascade-connected. In carrying out the construction of No. 2, first, of the two line amplifiers 1 located on both sides of the construction site 3, a spare terminal 5 different from the line connection terminal 4 to which the line 2 is connected is connected to an auxiliary amplifier. 6 is connected to the bypass line 7 to connect between the amplifiers 1 for both lines, then the line 2 between the amplifiers 1 for both lines is disconnected from the respective line connection terminals 4, and then first The bypass line 7 connected to the spare terminal 5 of each line amplifier 1 is switched and connected to the line connection terminal 4 of each of the line amplifiers 1 by a switch 8 such as a switch, a branching device, and a distributor. Connect between the line amplifiers 1, It is characterized in that in the state performing the work of construction places 3 of the line 2.

[0008]

In the line construction method of the present invention, the two line amplifiers 1 located on both sides of the construction site 3 are connected by the bypass line 7 connected to the spare terminal 5, and then the line 2 of the construction site 3 is connected to the line. Since the signal is disconnected from the line connection terminal 4 of the amplifier 1 for the line, the signal between the amplifiers 1 for both lines bypasses the bypass line 7 and is transmitted without delay.
By operating the bypass line 7 connected to the spare terminal 5
Is reconnected to the line connection terminal 4 without quality deterioration, the transmission quality deterioration is limited to a short time from the disconnection of the line 2 to the switching connection of the bypass line 7 to the line connection terminal 4. be able to.

[0009]

[Embodiment 1] FIG. 1 shows an embodiment of a method for constructing a railroad track of the present invention.
Shown in. This is a coaxial cable (line) 2 to the same cable 2
A transmission line of a CATV system in which a plurality of line amplifiers 1 for compensating and amplifying a signal attenuated by is connected in cascade, and a method of constructing a coaxial cable 2 in this transmission line will be described below.

First, a bypass line 7 is connected to a spare terminal 5 different from the line connecting terminal 4 to which the cable 2 of the two line amplifiers 1 located on both sides of the coaxial cable 2 having the construction site 3 is connected. To do. A connection cable 11 for connecting to the spare terminal 5 and a connection cable 12 for connecting to the line connecting terminal 4 are attached to both ends of the bypass line 7 so as to be switchable by a switch 8 (switch). A correction amplifier 6 for amplifying the signal output from the spare terminal 5 and correcting the frequency characteristic deviation is attached to the. The connection between the spare terminal 5 and the bypass line 7 is made by this connection cable 11. In this way, the signal output from the spare terminal 5 of the one line amplifier 1 flows through the correction amplifier 6 to the bypass line 7 and is input to the spare terminal 5 of the other line amplifier 1.

Next, the coaxial cable 2 between the amplifiers for both lines 1 is disconnected from the respective line connecting terminals 4 to stop the signal to the coaxial cable 2 having the construction site 3. At this time, the signal between the amplifiers 1 for both lines is transmitted by the bypass line 7 and the signal is continuously transmitted. However, since the output signal from the spare terminal 5 is used, the signal transmission quality is not so good.

Next, the connection cable 1 for the bypass line 7
Line connection terminal 4 of the line amplifier 1 in which 2 is disconnected first
Connect to. After that, the contact of the switch 8 of the bypass line 7 is promptly switched to from in the figure, and a high-quality signal output from the line connection terminal 4 of the line amplifier 1 is input to the bypass line 7 and the other line is input. The signal is sent to the line connection terminal 4 of the amplifier 1. In this state, even if the construction site 3 of the coaxial cable 2 is constructed, the quality of the signal transmitted via the bypass line 7 during the construction period is kept exactly the same as in normal times. Next, after the completion of construction, the contact of the switch 8 of the bypass line 7 is switched from to in the figure, and the signal of the spare terminal 5 is temporarily used, while the connection cable 12 is disconnected from the line connection terminal 4 and the line connection is made. The construction is completed when the coaxial cable 2 after construction is reconnected to the terminal 4 for construction.

[0013]

[Embodiment 2] FIG. 2 shows another embodiment of the method for constructing a track of the present invention. This also uses the transmission line of the CATV system as in the first embodiment, and the work procedure is also the same as in the first embodiment. However, a combiner is used as the switch 8. When a signal is input to the terminal, the multiplexer / distributor 8 multiplexes and outputs the signal from the terminal, and when a signal is input to the terminal, the signal from the terminal is distributed and output. To do. A branching device may be used as the switching device 8.

In the above embodiments, the transmission line of the CATV system is used, but the present invention can be applied to not only image transmission such as CATV but also data transmission. Further, not only the coaxial cable 2 but also the line 2 using a pair wire or an optical fiber can be implemented.

[0015]

According to the method of constructing a line of the present invention, it is possible to carry out construction without stopping transmission even during construction and with a minimum amount of time for impairing transmission quality.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a method for constructing a track of the present invention.

FIG. 2 is a schematic view showing another embodiment of the method for constructing a track of the present invention.

FIG. 3 is a schematic view showing an example of a conventional track construction method.

FIG. 4 is a schematic view showing another example of a conventional line construction method.

[Explanation of symbols]

 1 Line amplifier 2 Line 3 Construction site 4 Line connection terminal 5 Spare terminal 6 Auxiliary amplifier 7 Bypass line 8 Switch

Claims (1)

[Claims] 1. When constructing a line 2 such as a coaxial cable, a pair of lines, an optical fiber, etc. in which at least two or more line amplifiers 1 are cascade-connected, first, two lines located on both sides of the construction site 3 are to be constructed. Of the line amplifier 1, a spare terminal 5 different from the line connecting terminal 4 to which the line 2 is connected, and a bypass line 7 to which an auxiliary amplifier 6 is connected.
To connect between the amplifiers 1 for both lines, then disconnect the line 2 between the amplifiers 1 for both lines from the respective line connecting terminals 4, and then, first, the spare terminal 5 of each line amplifier 1. The bypass line 7 connected to is switched and connected to the line connection terminal 4 of each of the line amplifiers 1 by a switch 8 such as a switch, a branching device, and a combiner / distributor to connect between the line amplifiers 1. A construction method for a railway, characterized in that construction of the construction site 3 of the railway 2 is performed in this state.