JPH08237227A - Optical subscriber line system where increase of subscriber terminal is easy - Google Patents

Abstract

PURPOSE: To facilitate the increase of subscriber terminals in an optical subscriber line system where an exchange and a repeater are connected with an optical fiber transmission line. CONSTITUTION: A first optical parallel transmitter/receiver 12 connected to one end of the optical fiber transmission line 20, and a first interface device processing the connection o the first optical parallel transmitter/receiver with a circuit in the exchange are arranged in the exchange. A second optical parallel transmitter/receiver 31 connected to the other end of the optical fiber transmission line and a second interface device 32 processing the connection of the second optical parallel transmitter/receiver and plural subscriber terminals 41-4n are arranged in the repeater 30. Even if a pair of optical fibers become full with the subscriber terminals, easy correspondence to the increase of the subscriber terminals is realized by the increase of units as same as the conventional ones in the exchange and the repeater when a pair of other parallel optical fibers are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical subscriber line system for connecting a repeater unit accommodating a plurality of subscriber terminals and an exchange with an optical fiber transmission line, and more particularly to the addition of subscriber terminals. The present invention relates to an optical subscriber line system that can be easily performed.

[0002]

2. Description of the Related Art As a conventional optical subscriber line system, for example, there is one described in JP-A-4-339430. That is, as shown in FIG.
Transmission between the relay device 106 and the repeater 106 is performed by two sets of optical
Electric conversion elements 103 and 107 and electric-optical conversion element 10
The main configuration is that of the optical fibers 105 and 105. In the case of adopting such a configuration, assuming that the number of subscribers is 4, as shown in FIG. 5, for example, in the relay device 106, as shown in FIG. There are 4 distributors 114 and 4: 1 combiners 115.

[0003]

In the above-mentioned conventional optical subscriber line system, in order to double the number of subscribers to eight without deteriorating the transmission capacity for each subscriber, the switching center 101 and Since it is necessary to double the transmission capacity with the relay device 106, the optical-electrical conversion elements 103, 107
It is necessary to replace the electro-optical conversion elements 104 and 108 with a high-performance element having twice the operating speed as before. Further, the distribution device 114 and the coupling device 11 in the relay device 106.
5 also needs to have double operating speeds, respectively, and as shown in FIG. 7, 1: 8 distributors 116 and 8:
1 must be replaced with the coupling device 117. Therefore, there is a drawback that the cost becomes high when the number of subscribers is increased.

In view of the above-mentioned drawbacks, the present invention minimizes the parts / devices that need to be replaced or added when the number of subscribers is increased, and the parts / devices that need to be replaced or added are almost the same as the conventional ones. It is an object of the present invention to provide an optical subscriber line system that can be realized with the above technology and can minimize the high cost when adding subscribers.

[0005]

SUMMARY OF THE INVENTION An optical subscriber line system of the present invention is an optical subscriber line system in which an exchange and a relay device accommodating a plurality of subscriber terminals are connected by an optical fiber transmission line. A first optical parallel transmission / reception device arranged in the exchange station and connected to one end of the optical fiber transmission line; and a first optical parallel transmission / reception device arranged in the exchange station and the inside of the exchange station. A first interface device for processing the connection with the circuit, a second optical parallel transmitter-receiver connected to the other end of the optical fiber transmission line, and arranged in the repeater, It has a second optical parallel transmission / reception device and a second interface device for processing the connection with the plurality of subscriber terminals.

The first and second optical parallel transmitter / receivers transmit / receive the transmission signals of the four subscriber terminals by a pair of optical fibers, and each time the pair of optical fibers to be used is increased, It is preferable that the transmission capacity for four subscriber terminals is increased.

[0007]

Since the switching station and the repeater are provided with the first and second optical parallel transmission / reception devices, respectively, even if a pair of optical fibers are filled with subscriber terminals, the parallel optical fibers are connected. If a pair is used, it is possible to easily cope with the increase in the number of subscriber terminals by increasing the number of devices in the switching station and the relay station as in the conventional case.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a block diagram showing an embodiment of the optical subscriber line system of the present invention, and FIG. 2 is a block diagram showing the repeater of FIG. 1 in detail. In the present embodiment, the switching center 10 and the relay device 3 connected to the switching center 10 via the optical fiber transmission line 20.
0 and a plurality of subscriber terminals 4 accommodated in the relay device 30.
1, 42, ..., 4n. Exchange 10
Has an interface device 11 for processing the connection with the inside of the exchange 10 and an optical parallel transmission / reception device 12 for connecting the interface device 11 and the optical fiber transmission line 20. The relay device 30 includes an optical parallel transmitter / receiver 31 connected to the optical fiber transmission line 20, and an interface device 32 connecting the optical parallel transmitter / receiver 31 and the subscriber terminals 41, 42, ..., 4n.

In this embodiment, the optical parallel transmitter / receivers 12, 3 are used.
1 has a function of transmitting and receiving four parallels, and each column has four subscribers. As shown in FIG. 2, it is assumed that at the first time point, only one of the four parallel optical transmission / reception devices 12 and 31 is actually operated and communication for four subscribers is performed ( See FIG. 2). The configuration of the relay device 30 is as shown in FIG. That is, the optical parallel transmitter / receiver 31
Both the receiving unit 311 and the transmitting unit 312 having four parallels among the above use only one path and the other three paths are in an idle state. Further, the interface device 32 is provided with a 1: 4 distributor 321 and a 4: 1 coupling device 325. The serial signal SS11 and the parallel signal PS11 are data sent to the four subscriber terminals, and are the parallel signal PS12 and the serial signal SS.
12 is data transmitted from the four subscriber terminals.

In the configuration shown in FIG. 2, when the number of subscriber terminals is changed from 4 to 8, as shown in FIG. 3, two of the 4 parallel paths in the optical parallel transmitter / receiver 6 are used. , And the interface device 32 includes a distributor 321
And in addition to the coupling device 325, another dispensing device 322 and a coupling device 326 are arranged respectively. Thus, additional dispensing device 322 and coupling device 326 are required, which may be similar to dispensing device 321 and coupling device 325, respectively, and are easily accommodated.

The optical parallel transmitter / receiver 3 used here
For example, the structure described in Japanese Patent Application Laid-Open No. 4-107017 may be applied as the structure 1 to have the structure shown in FIG. That is, the receiving unit 311 uses each pin.
Photodiodes are connected to the optical fibers 21, 22, 23, 24 of the optical fiber transmission line 20, and a pin photodiode array 50, and amplifier circuits 61, 62, 63, 64 for amplifying the output of each pin photodiode, and amplification. The distributor 3 identifies the logical level ("0" or "1" of the digital signal) from the outputs of the circuits 61, 62, 63, 64.
And an identification circuit for outputting to 21. In addition, the transmission unit 31
2 is the optical fibers 25, 26 of the optical fiber transmission line 20,
A light emitting diode array 90 including light emitting diodes connected to each of the light emitting diodes 27 and 28, and drive circuits 81, 82, 83 and 84 for driving the respective light emitting diodes of the light emitting diode array 90 in response to a signal from the coupling device 325. The transmitter 33 includes a light emitting diode array 34 and drive circuits 35 to 39, and the receiver 50 includes a pin photodiode array 51, amplifier circuits 57 to 61, and an identification circuit 62.
It consists of ~ 66.

[0012]

As described above, according to the present invention, when the number of subscribers is increased, the optical-electrical conversion element and the electric-optical conversion element are added to the repeater without changing to high performance ones. Since the distribution device and the coupling device each need to have the same operating speed as the conventional one, it is possible to reduce the cost increase when the number of subscribers is increased.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an optical subscriber line system of the present invention.

FIG. 2 is a block diagram showing a relay device of the embodiment of FIG.

3 is a block diagram showing an example when the number of subscriber terminals is increased in the relay device of FIG.

FIG. 4 is a block diagram showing an example of an optical parallel transmitter / receiver that can be used in the embodiment of FIG.

FIG. 5 is a block diagram showing a conventional example of an optical subscriber line system.

FIG. 6 is a diagram showing the contents of a relay device in the conventional example of FIG.

FIG. 7 is a diagram showing the contents of the relay device when the number of subscriber terminals is increased in the conventional example of FIG.

[Explanation of symbols]

 10 switching center 11, 32 interface device 12, 31 optical parallel transmitter / receiver 20 optical fiber transmission line 21-28 optical fiber 30 repeater 41, 42, ..., 4n subscriber 50 pin photodiode array 61-64 amplification circuit 71-74 Identification circuit 81 to 84 Drive circuit 90 Light emitting diode array 311 Receiver of optical parallel transmitter / receiver 312 Transmitter of optical parallel transmitter / receiver 321,322 Distribution device 325,326 Coupling device

Claims (2)

[Claims] 1. An optical subscriber line system in which an exchange station and a relay device accommodating a plurality of subscriber terminals are connected by an optical fiber transmission line, wherein the optical fiber transmission line is arranged in the exchange station. A first optical parallel transmitter / receiver connected to one end of the first optical parallel transmitter / receiver, and a first interface device disposed in the switching center for processing a connection between the first optical parallel transmitter / receiver and a circuit inside the switching center; A second optical parallel transmitter / receiver arranged in the repeater and connected to the other end of the optical fiber transmission line; and a second optical parallel transmitter / receiver arranged in the repeater and the plurality of subscriber terminals. An optical subscriber line system having a second interface device for processing a connection. 2. The first and second optical parallel transmission / reception devices,
Each time the transmission signal of four subscriber terminals is transmitted and received by a pair of optical fibers and the pair of optical fibers to be used is increased,
The optical subscriber line system according to claim 1, wherein transmission capacity for four subscriber terminals is increased.