JPH02276327A - Optical data transmission equipment - Google Patents

Abstract

PURPOSE:To dispense with the checking of every reception data at a user side by transmitting transmission data after converting to an optical signal with wavelength band lambda1 and the one with wavelength lambda2, comparing the light receiving levels of the optical signals with wavelength at the reception side, and always outputting the reception data reproduced from the signal with a higher light receiving level to a user. CONSTITUTION:The transmission data is converted to the optical signals with different wavelength band lambda1 and lambda2, respectively by a first optical transmitter 8 and a second optical transmitter 9, and they are synthesized by an optical multiplexer 10, then, it is transmitted via an optical fiber 11, and is demultiplexed at every wavelength band by an optical demultiplexer 12, and the optical signal with the wavelength band lambda1 is inputted to a first optical receiver 13, and the optical signal with the wavelength band lambda2 to a second optical receiver 14, respectively. A level comparator 16 always compares the light receiving level of the first optical receiver 13 with that of the second optical receiver 14, and controls an out put selection circuit 15 so as to output the signal of the optical receiver with a higher light receiving level to the user. In such a way, it is not required to always check the reception data at the user side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical data transmission device that transmits information using an optical fiber.

[Conventional technology]

FIG. 2 is a diagram showing a conventional optical data transmission device. In FIG. 9, (1) and (2) are third and fourth optical transmitters that convert electrical signals into optical signals, respectively.

(3) and (4) are the first and second optical fibers that transmit the optical signal, respectively, and (5) and (6) are the third and fourth optical receivers that regenerate the original electrical signal from the optical signal, respectively. (7) is the third optical receiver (5) and the fourth optical receiver (7).
This is a switch for selecting one of the reproduced signals of the optical receiver (6).

Next, the operation will be explained.

The transmission data is converted into an optical signal by a third optical transmitter (11) and a fourth optical transmitter (2), and is transmitted via a first optical fiber (3) and a second optical fiber (4), respectively. hand,
a third optical receiver (5) and a fourth optical receiver (
6).

The third optical receiver (5) and the fourth optical receiver (6) each regenerate the original electrical signal from the received optical signal and output it to the switch (7). The switch (7) selects the reproduced signal from either the third optical receiver (5) or the fourth optical receiver (6) and outputs it to the user as received data.

By the way, since the user selects the reproduction signal by operating the switch (7), for example, the switch (9) is selected.
7) selects the reproduced signal of the third optical receiver (5) and outputs it as received data, due to a failure of the third optical transmitter (1), etc., the signal is input to the third optical receiver. When the remaining optical signal disappears, normal reception data cannot be obtained from the third optical receiver (5). Therefore, the user must always check whether or not normal data is being received, and if an abnormality is detected, the user must operate the switch (7) to switch to the other normal transmission system.

[Problem to be solved by the invention]

Since the conventional optical data transmission equipment is configured as described above, the user must constantly check whether data transmission is being performed normally in the transmission system selected by the switch (7), and also check whether there is an abnormality. is detected, switch (
There was a problem in that the transmission system had to be switched by operating 7).

The present invention has been made to solve the above-mentioned problems, and does not require the user to constantly check for abnormalities in received data.

The object of the present invention is to provide an optical data transmission device that does not require a user to switch transmission systems.

[Failure to solve the problem]

The optical data transmission device according to the present invention converts transmission data into optical signals of different wavelength bands λ1 and λ2 on the transmitting side and transmits them, and on the receiving side compares the received light levels of the optical signals of the respective wavelength bands and A selection circuit selects the reproduced signal of the optical receiver receiving the higher level optical signal and outputs it to the user as received data.

[Effect]

In the optical data transmission device of the present invention, the data reproduced from the optical signal with the higher received light level is always selected and output to the user, so the user does not need to constantly check the received data, and the user There is no need to switch the transmission system.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, (8) and (9) are first and second optical transmitters that convert electrical signals into optical signals in different wavelength bands λ1 and λ2, respectively, and α[ is an optical signal in wavelength bands λ1 and λ2. αυ is an optical fiber that transmits the optical signal output from combiner α1, (I3 is optical fiber α
An optical demultiplexer separates the combined optical signal of the wavelength bands λ1 and λ2 of υ into optical signals of each wavelength band and outputs them to independent ports, αJ is the wavelength band λ1 of the demultiplexer a3.
(I4 is a second optical receiver that regenerates the original electrical signal from the optical signal output in the wavelength band λ2 near the demultiplexer 0.) , α9 is the first
an output selection circuit that selects and outputs one of the electrical signals reproduced by the optical receiver 0 and the second optical receiver I;
αe is a level at which the output selection circuit α3 outputs a control signal by constantly comparing the light reception levels of the first optical receiver a3 and the second optical receiver α4 and selecting the signal of the optical receiver with the higher light reception level. This is a comparison circuit.

Next, the operation will be explained.

Transmission data is converted into optical signals of different wavelength bands λ1 and λ2 by a first optical transmitter (8) and a second optical transmitter (9), respectively, and combined by an optical multiplexer. It is transmitted via fiber αυ. Then, the nine combined optical signals are demultiplexed into each wavelength band by an optical demultiplexer @, and the optical signal in the wavelength band λ1 is sent to the first optical receiver 0, and the optical signal in the wavelength band λ2 is sent to the second optical receiver 0. are respectively input to the optical receiver α4. The level comparison circuit αe constantly compares the light reception level of the first optical receiver and the light reception level of the second optical receiver α.

The output selection circuit is controlled so that the signal from the optical receiver with the higher received light level is output to the user.

For example, the first optical transmitter (8) has failed and the wavelength band λ
When the first optical signal dies out, the level of light received by the first optical receiver αj drops significantly compared to the level of light received by the second optical receiver a4. The output selection circuit (US
control. Even if the second optical transmitter (9) fails, the output signal of the first receiver is automatically selected and output in a similar operation, so there is no need for the user to constantly check the received data.

Further, there is no need for the user to switch the received data.

Note that although optical signals in two wavelength bands are used in the above embodiments, optical signals in two or more wavelength bands may be used.

〔Effect of the invention〕

As described above, according to the present invention, transmission data is converted into optical signals in different wavelength bands λ1 and λ2 and transmitted on the transmitting side, and the reception level of the optical signals in the respective wavelength bands is compared on the receiving side. Since the configuration is such that the received data that is always reproduced from the optical signal with the higher received light level is output to the user, the user does not need to constantly check the received data, and the user can also disconnect the transmission system. It has the advantage that no changing operation is required.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an optical data transmission device according to an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional optical data transmission device. In the figure, (1) is the third optical transmitter, (2) is the fourth optical transmitter, (3) is the first optical fiber, (4) is the second optical fiber, and (5) is the fourth optical fiber. 3 is the optical receiver, (6) is the fourth optical receiver, (7) is the switch, (8) is the first optical transmitter, (9) is the second optical transmitter, α0 is the optical multiplexer , αυ is an optical fiber. (L is the optical demultiplexer, α is the first optical receiver, I is the second optical receiver, α9 is the output selection circuit, and αe is the level comparison circuit. Parts are shown with the same reference numerals.

Claims (1)

[Claims] First and second optical transmitters that convert electrical signals into optical signals in different wavelength bands λ_1 and λ_2, respectively, and are connected to the first and second optical transmitters to combine optical signals in wavelength bands λ_1 and λ_2. an optical multiplexer that transmits an optical signal, an optical fiber that is connected to this optical multiplexer and transmits an optical signal, and an optical signal that is connected to this optical fiber and combines the optical signals of wavelength bands λ_1 and λ_2, and the optical signals of the respective wavelength bands. There is an optical demultiplexer that demultiplexes the signals and outputs them to independent ports, and an optical demultiplexer that separates the wavelength band λ_1 and outputs the wavelength band λ_1.
a first optical receiver that regenerates the original electrical signal from the optical signal of wavelength band λ_2; an output selection circuit that selects and outputs one of the electrical signals reproduced by the first and second optical receivers; and a light reception level of the first and second optical receivers. and a level comparison circuit that outputs a control signal so that the selection circuit selects a signal from an optical receiver having a high received light level.