JPH05122237A - Optical communication system - Google Patents

Abstract

PURPOSE:To provide a high transmission efficiency by quickening the response from the non-signal state till the start of signal input without imposing a heavy load onto a receiver. CONSTITUTION:Plural stations 15-17 each having an optical transmitter T and an optical receiver R are interconnected through a star coupler 14, and an optical signal corresponding to logic data outputted from any of the optical transmitters T is branched by the star coupler 14 and sent to the optical receiver R of each station. In the optical communication system as above, the system is provided with a station 11 connecting to the plural stations 15-17 via the star coupler 14 and a main transmitter T of the station 11 sends continuously a regular monitor signal and the receivers R of the plural stations 15-17 making data transmission are operated synchronously with the monitor signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passive star type optical communication system using a star coupler, and more particularly to an optical communication system for improving the response of data transmission.

[0002]

2. Description of the Related Art Conventionally, in this type of optical communication system, a plurality of stations having a transmitter / receiver are connected in a star shape by using installed optical fiber cables for transmission and reception and a star coupler to form an optical communication network. Then, an optical signal output from an optical transmitter of a certain station to an optical communication network is branched by a star coupler, and data is transmitted by allowing the receiver of each station to capture the branched optical signal. there were.

[0003]

However, in the above optical communication system, when the output of the transmitter of a certain station is taken in by all the receivers, in order to improve the communication efficiency, the signal input from the no-signal state is performed. A quick response at the start is required. For this reason, in the receiver, there is a problem that the load at the time of performing the optical / electrical conversion and the clock signal reproduction becomes large, the circuit scale becomes large, and the manufacturing cost becomes high.
Further, a receiver having a simple structure has a problem that it takes a long time to start up and the transmission efficiency is lowered.

When the transmitter and the receiver perform optical communication in a one-to-one opposition, in order to speed up the response, even when there is no data to be transmitted, a meaningless code is continuously sent to receive the above reception. It is often used to keep the receiver in a receiving state and to delay the start-up only when the system is started up. In the passive star type optical communication system, when one transmitter is transmitting, Another problem is that data collision occurs when another transmitter starts transmission.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical communication system capable of obtaining high transmission efficiency without imposing a heavy burden on the receiver.

[0006]

In order to achieve the above object, according to the present invention, a plurality of transmitting / receiving means are connected via a star coupler, and an optical signal corresponding to logical data output from any one of the transmitting / receiving means. In the optical communication system in which a signal is branched by the star coupler and transmitted to each of the transmitting / receiving means, a transmitting means is provided for connecting to a plurality of transmitting / receiving means via the star coupler, and the transmitting means supplies a regular monitor signal. An optical communication system is provided in which the transmitting / receiving means for continuously transmitting and transmitting data operates in synchronization with the monitor signal.

[0007]

The transmitter, which is the transmitting means, transmits the monitor signal to the optical communication network even in the non-signal state. Therefore, the transmitter / receiver, which is a transmitter / receiver for performing data transmission, operates in synchronization with the monitor signal, and the responsiveness at the start of signal input can be increased from the above-mentioned no-signal state.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a configuration diagram showing a configuration of an optical communication network using the optical communication system of the present invention. In the figure, an optical communication network 10 includes a station 11 having a main transmitter T, and stations 15 to 17 having an optical transmitter T and a receiver R.
The main transmitter T, the optical transmitter T, and the optical receiver R are provided with the transmission optical fiber cable 12, the reception optical fiber cable 13, and the star coupler 14 which are installed. It is connected.

The main transmitter T is the optical fiber cable 1 described above.
A predetermined regular monitor optical signal for synchronization as shown in FIG. 2 (a) is constantly transmitted to the optical communication network via the communication line 2. Each of the stations 15 to 17 which performs data transmission takes in the monitor signal output to the optical communication network, operates each receiver R in synchronization with the monitor signal,
The transmitter T transmits the optical signal corresponding to the logical data and the receiver R receives the optical signal.

That is, each of the stations 15 to 17 fetches the monitor signal constantly transmitted from the main transmitter T of the station 11, operates the receiver R constantly in synchronization with the monitor signal, and starts the operation from the predetermined transmitter T. When an optical signal as shown in 2 (b) is transmitted to the optical communication network, the receiver R operating is
As shown in FIG. 2 (c), the optical signal can be captured.

Therefore, in this embodiment, all the receivers on the optical communication network can be always activated by the monitor signal, so that the responsiveness of the optical signal to the data transmission can be accelerated.

[0012]

As described above, in the present invention, a plurality of transmitting / receiving means are connected via a star coupler, and an optical signal corresponding to logical data output from any of the transmitting / receiving means is transferred to the star coupler. In the optical communication system of branching with and transmitting to each of the transmitting and receiving means, a transmitting means is provided that is connected to a plurality of transmitting and receiving means via the star coupler, and the transmitting means continuously transmits a regular monitor signal, Since the transmitting / receiving means for transmitting data operates in synchronization with the monitor signal, the response to data transmission is accelerated,
Therefore, high transmission efficiency can be obtained without imposing a heavy burden on the receiver.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an optical communication network using an optical communication system of the present invention.

FIG. 2 is a waveform diagram showing signals in each unit shown in FIG.

[Explanation of symbols]

 11, 15 to 17 stations 12 optical fiber cable for transmission 13 optical fiber cable for reception 14 star coupler T transmitter R receiver

Claims (1)

[Claims] 1. A plurality of transmitting / receiving means are connected via a star coupler, and an optical signal corresponding to logical data output from any of the transmitting / receiving means is branched by the star coupler and transmitted to each transmitting / receiving means. In the optical communication system
Providing transmission means connected to a plurality of transmission / reception means via the star coupler, the transmission means continuously transmits a regular monitor signal, and the transmission / reception means for data transmission operates in synchronization with the monitor signal. An optical communication system characterized by: