JPH0630472B2 - Optical burst mode time division transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] In an optical burst mode time division transmission device (optical ping-pong transmission device) having one photoelectric conversion element that converts light into electricity and electricity into light, By making the self-emission wavelength the same as the self-emission wavelength of the other photoelectric conversion element, the transmission distance can be increased without lowering the light-receiving sensitivity.

[Industrial application field]

The present invention relates to an improvement of an optical burst mode time division transmission device having one photoelectric conversion element that converts light into electricity and electricity into light.

In the optical burst mode time division transmission device, it is desirable that the light receiving sensitivity does not decrease.

As shown in FIG. 7, the light receiving sensitivity of a photoelectric conversion element such as a light emitting diode (hereinafter referred to as an LED) and a laser diode is as shown in FIG. It is known that when the distance is shortened to λ2, the photoelectric conversion efficiency is poor and the light receiving sensitivity is lowered.

[Conventional technology]

 A conventional example will be described below with reference to the drawings.

FIG. 6 is a block diagram of a main part of a conventional optical burst mode time division transmission system.

When burst transmission data SD1 is input to the master side optical burst mode time division transmission device shown in (A), LED1 is driven by the drive circuit 3 to become an optical signal, which passes through the optical fiber 20 and is shown in (B). It is sent to the optical burst mode time division transmission device on the slave side, received by the LED 1 ', electrically converted, and received as reception data RD2 via the receiving section 9'.

Further, in the optical burst mode time division transmission device on the slave side shown in (B), when the burst transmission data SD2 is input,
The LED 1'is driven by the drive circuit 8'to become an optical signal,
It is sent to the master side optical burst mode time division transmission device shown in FIG. 4A through the optical fiber 20, received by the LED 1 and electrically converted, and is received as the reception data RD1 via the receiving unit 9.

The transmission from the master side and the transmission from the slave side are
As shown in (C), the data is transmitted from the master side in a time division manner so that the data is transmitted after the guard time has elapsed.

In this way, communication is performed by performing so-called ping-pong transmission using one optical fiber 20.

[Problems to be solved by the invention]

However, LED1 on the master side and LE on the slave side
The emission wavelength of D1 'does not always match.

For example, if the emission wavelength of the slave LED 1'is shorter than that of the master LED 1, the slave LED 1 '
1'has a problem that the light receiving sensitivity is lowered and the transmission distance is shortened as shown in FIG.

[Means for solving problems]

As shown in the principle block diagram (A) of FIG. 1, the above-mentioned problems include a wavelength monitor circuit 2 for monitoring the self-emission wavelength and a multiplexing circuit 3 for multiplexing the monitored wavelength data on the transmitting side. A separation circuit 4 for separating wavelength data from the received data, a wavelength data receiving circuit 5 for receiving the separated wavelength data, and a self-emission wavelength are controlled to be equal to the received wavelength based on the received wavelength data on the receiving side. An emission wavelength control circuit 6 and a selection circuit 7 for selecting whether or not to control the self-emission wavelength are provided, or when used as a master side, as shown in (B),
On the transmission side, a wavelength monitor circuit 2 that monitors the self-emission wavelength and a multiplexing circuit 3 that multiplexes the monitored wavelength data.
When used as a slave side, as shown in (C), a separation circuit 4 for separating wavelength data from reception data on the reception side is provided.
And the light of the present invention including a wavelength data receiving circuit 5 for receiving the separated wavelength data and an emission wavelength control circuit 6 for controlling the self-emission wavelength to be equal to the received wavelength based on the received wavelength data. It is solved by a burst mode time division transmission apparatus.

[Action]

In FIG. 1 (A), the selection circuit 7 selects the one that controls the self-emission wavelength when it is the slave side, and the one that does not control the self-emission wavelength when it is the master side. Therefore, according to the present invention, even if the optical burst mode time division transmission device shown in (A) is used on the master side and the slave side,
Even if the optical burst mode time division transmission apparatus shown in (B) is used on the master side and the optical burst mode time division transmission apparatus shown in (C) is used on the slave side, the wavelength of the photoelectric conversion element on the slave side is transmitted. Since the emission wavelength control circuit 6 controls the wavelengths of the photoelectric conversion elements on the master side to be equal to each other, the emission wavelengths of the photoelectric conversion elements on the master side and the slave side are equal, and the light receiving sensitivity is Never decreases,
The transmission distance is never shortened.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a block diagram of a main part of an optical burst mode time division transmission apparatus according to an embodiment of the present invention, and FIG. 3 is a diagram showing a frame format in the case of FIG.

FIG. 2 shows an optical burst mode time division transmission device which can be used on either the master side or the slave side.
As a method of controlling the emission wavelength of the LED 1, there are a method of changing the ambient temperature and a method of changing the bias current. FIG. 2 shows an example of controlling the emission wavelength by changing the ambient temperature. There is.

In FIG. 2, the temperature of the constant temperature bath 10 for the LED 1 is measured by the sensor 1
1, the analog / digital converter 12 converts it into a digital signal, and the wavelength data creating circuit 13 creates wavelength data converted from this temperature, and the multiplexing circuit 3
At the same time, it is multiplexed with the burst data and becomes a signal of a frame mat composed of the frame pattern, the wavelength data and the data shown in FIG. 3, and the drive circuit 8 drives the LED 1 to make it an optical signal, which is transmitted through the optical fiber 20. To be done.

The optical signal sent from the optical fiber 20 is received by the LED 1, received by the receiving unit 9, separated into data and wavelength data by the separation circuit 4, and the wavelength data is received by the wavelength data reception circuit 5. The temperature data creation circuit 14 creates data on how much temperature should be used to match the wavelength of the LED 1 in the constant temperature bath 10 with this wavelength data, and the digital / analog converter 15 can be created. Converted into an analog value and sent to the error detection circuit 16.

An analog value of the temperature is input from the sensor 11 to the error detection circuit 16, and an error between this and the output of the digital-analog converter 15 is detected, and the error becomes 0 via the temperature control circuit 17. As described above, the current flowing through the heater 18 is controlled, and the wavelength of the LED 1 is controlled so as to match the wavelength of the transmitted wavelength data.

Therefore, since the wavelength of the LED 1 matches the wavelength of the LED on the other side, the reception sensitivity does not decrease and the transmission distance does not become short.

However, when this optical burst mode time-division transmission device is used on the master side, it is not necessary to control the wavelength of the LED 1, and therefore a selection circuit 10 is provided to select one which does not perform this control.

The temperature data creation circuit 14, the digital / analog converter 15, the error detection circuit 16, the temperature control circuit 17, the heater 18, and the sensor 11 constitute the emission wavelength control circuit 6 shown in FIG. The analog / digital converter 12 and the wavelength data creating circuit 13 are used to monitor the wavelength monitor circuit 2.
Are configured.

Next is the configuration of the optical burst mode time division transmission device when it is used only on the master side and the slave side.
This will be described with reference to FIG.

FIG. 4 is a block diagram of a main part of the master side optical burst mode time division transmission apparatus according to the embodiment of the present invention, and FIG. 5 is a block diagram of the slave side optical burst mode time division transmission apparatus according to the embodiment of the present invention. It is a block diagram of a part.

In order not to reduce the receiving sensitivity and not shorten the transmission distance,
Since the wavelength data of the LED is sent from the master side so that the wavelength of the LED on the slave side matches the wavelength of the LED on the master side, the master side multiplexes the wavelength data of LED1 with the burst data. It is necessary to transmit, but it is not necessary to control the wavelength of the LED 1. Therefore, as shown in FIG. 4, the multiplexing circuit 3, the sensor 11, the analog / digital converter 12, and the wavelength data creating circuit 13 shown in FIG.
Since the slave side must control the wavelength of LED1 'so as to match the wavelength of LED1 on the master side, the slave side does not have to transmit the wavelength of LED1'. As shown in FIG. 2, on the receiving side, the separation circuit 4, the wavelength data reception circuit 5, the temperature data creation circuit 14, the digital / analog converter 15, the error detection circuit 16, the temperature control circuit 17, the heater 18, shown in FIG. It suffices if the sensor 11 'is provided.

The operation of each part is the same as that described in FIG.
Since the wavelengths of 1 and LE1 'are the same, the receiving sensitivity does not decrease and the transmission distance does not decrease.

〔The invention's effect〕

As described in detail above, according to the present invention, since the wavelength of the LED is the same as that of the other side, the reception sensitivity does not decrease,
The transmission distance is not shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of essential parts of an optical burst mode time division transmission apparatus according to an embodiment of the present invention, and FIG. 3 is a diagram showing a frame format in the case of FIG. FIG. 4 is a block diagram of a main part of an optical burst mode time division transmission apparatus on the master side according to the embodiment of the present invention, and FIG. 5 is a block diagram of an optical burst mode time division transmission apparatus on the slave side according to the embodiment of the present invention. 6 is a block diagram of a main part of a conventional optical burst mode time division transmission system, and FIG. 7 shows light receiving sensitivity when the light emitting wavelength of the light receiving LED is changed with respect to the light receiving light wavelength λ1. It is a figure. In the figure, 1, 1'is a photoelectric conversion element, a light emitting diode, 2 is a wavelength monitor circuit, 3 is a multiplexing circuit, 4 is a separation circuit, 5 is a wavelength data receiving circuit, 6 is an emission wavelength control circuit, and 7 is a selection circuit. Circuit, 8, 8'drive circuit, 9, 9'reception unit, 10, 10 'thermostatic chamber, 11, 11' sensor, 12 analog / digital converter, 13 wavelength data generation circuit, 14 A temperature data generation circuit, 15 is a digital / analog converter, 16 is an error detection circuit, 17 is a temperature control circuit, and 18 is a heater.

Claims (2)

[Claims] 1. A wavelength monitor circuit for monitoring a self-emission wavelength on a transmitting side in an optical burst mode time division transmission device having one opto-electric conversion element (1) for converting light into electricity and converting electricity into light. (2) and a multiplexing circuit (3) for multiplexing the monitored wavelength data, a separation circuit (4) for separating the wavelength data from the received data on the receiving side, and a wavelength data reception for receiving the separated wavelength data A circuit (5), an emission wavelength control circuit (6) for controlling the self-emission wavelength to be equal to the received wavelength based on the received wavelength data, and a selection circuit for selecting whether or not to control the self-emission wavelength. An optical burst mode time division transmission device comprising (7). 2. An optical burst mode time division transmission device having one photoelectric conversion element (1) for converting light into electricity and converting electricity into light, when used as a master side, when it is used as a master side, the transmitting side itself A wavelength monitor circuit (2) for monitoring the emission wavelength and a multiplexing circuit (3) for multiplexing the monitored wavelength data are provided, and when used as a slave side, the receiving side separates the wavelength data from the received data. A circuit (4), a wavelength data receiving circuit (5) for receiving the separated wavelength data, and an emission wavelength control circuit (6) for controlling the self-emission wavelength to be equal to the received wavelength based on the received wavelength data.
An optical burst mode time-division transmission device characterized by comprising: