JPH05114908A - Loop transfer network system - Google Patents

Abstract

PURPOSE:To obtain a loop transfer network system having high flexibility a low cost by re-constructing a loop extremely simply and within very short time without requiring large scale construction. CONSTITUTION:In addition to plural terminal connection equipments CN1 to CN8 having a loop transfer function, respectively, and dispersedly located at arbitrary positions, a terminal equipment TM is provided. Input transfer pathes ILN1 to ILN8 and output transfer pathes OLN1 to OLN8 to be connected to the plural terminal connection equipments C1 to CN8, respectively, are led to the terminal equipment TM. In the terminal equipment TM, the input transfer pathes ILN1 to ILN8 and the output transfer pathes OLN1 to OLN8 are selectively connected by means of connection optical fibers CBO to CB9. Thus, the loop transfer network passing through the respective terminal connection equipments CN1 to CN8 can be constructed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, an optical LAN (Loca).
l Area Network) system and MAN (Metropolitan Are)
a network) system, which relates to a loop transmission network system for transmitting information by connecting a plurality of terminal devices in a loop via a transmission path.

[0002]

2. Description of the Related Art In recent years, various communication systems have been developed in accordance with an increase in communication needs and the development of technology, and among them, there is a loop transmission network system. This type of system is different from a system in which a plurality of terminal devices are selectively connected via an exchange to perform communication, and a plurality of terminal devices are connected in a loop via a transmission line, and a terminal device of a transmission source is connected. Is sent to the loop with a destination address attached to the transmission information, and the terminal device waiting to receive determines whether or not the transmission information being transmitted on the loop is addressed to itself by the destination address, It is a system configured to capture this transmission information when it is addressed to itself.

FIG. 7 is a schematic diagram showing an example of the configuration of this type of system. This system has a first optical loop transmission network LP1 and a second optical loop transmission network LP2, and these networks LP1, LP
The two are connected via an inter-loop transmission line LN3. First and second optical loop transmission network LP
1, LP2 are terminal devices DT11 to DT1m,
A plurality of terminal connection devices CN11 to CN1m and CN21 to CN2n that form a terminal device together with DT21 to DT2n.
Optical transmission lines LN1 and L using optical fiber cables
The terminal devices DT11 to DT1m and DT21 to DT2n are connected to the terminal connection devices CN11 to CN1m and CN21 to CN2n, respectively. Note that LCN1 and LCN2 are the first and second optical loop transmission networks LP11 and LP21, respectively.
It is an inter-loop connecting device for connecting between the loops. Since this type of system does not require an exchange, it has an advantage that it can be constructed relatively easily and inexpensively as compared with a circuit switching network.

[0004]

However, this type of system has a problem in that when a loop is reconfigured, that is, a single loop is made into a plurality of loops, a plurality of loops is made into a single loop, or a loop route is changed. There was a problem that large-scale construction was required each time. For example, in the system shown in FIG. 7, the second optical loop transmission network L
When P2 is divided into two loops LP2a and LP2b, the terminal connecting devices CN21 and CN2 as shown in FIG.
New optical transmission lines (solid line a in the figure) are respectively laid between the i and the inter-loop connecting device LCN21 and the terminal connecting device CN2i + 1, and further between the inter-loop connecting device LCN21 and the terminal connecting device CN21 and Terminal connection device CN2
The unnecessary optical transmission line between the i and CN2i + 1 (two-dot chain line B in the figure) had to be removed in some cases.
Note that LCN22 and LCN23 are inter-loop connecting devices for connecting between the loop transmission networks LP2a and LP2b newly formed by division, and LN4 is the inter-loop transmission line.

These constructions are extremely complicated and large-scale, especially when it is necessary to lay a transmission line under a public road in an overcrowded area such as a downtown area or an urban area, which requires a large construction cost. .. At the same time, the construction also caused traffic congestion and congestion of underground buried objects, which was a big problem.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to reconfigure a loop extremely easily and in a short time without requiring a large-scale construction. To provide a loop transmission network system that is cheaper and more flexible.

Another object of the present invention is to provide, in addition to the above objects, a loop transmission network system capable of suppressing the influence of a failure even if a failure occurs.

Still another object of the present invention is to provide a loop transmission network system which, in addition to the above objects, can easily perform not only reconfiguration of a loop but also new construction and extension of a loop.

[0009]

In order to achieve the above object, the present invention provides a terminal device separately from a plurality of terminal devices each having a function for loop transmission and distributed and arranged at an arbitrary position. To do. Then, the input transmission lines and the output transmission lines respectively connected to the plurality of terminal devices are respectively guided to the terminal device, and in the terminal device, the input transmission lines and the output transmission lines are selectively connected. As a result, a loop transmission network passing through each of the above terminal devices is configured.

In order to achieve the above other object, the present invention guides each terminal device to a terminal device when the loop transmission network system is bidirectionally configured by using two pairs of transmission lines. Another feature is that two pairs of transmission lines are laid on different routes.

In order to achieve the above-mentioned another object, the present invention is provided in the case where an existing circuit switching network exists.
The terminal device is installed in a switching center of the circuit switching network, and the input transmission line and the output transmission line of each terminal device are laid by sharing at least a part of the existing line equipment of the circuit switching network, and the terminal device is installed. It is also characterized in that it leads to.

[0012]

As a result, according to the present invention, all the transmission lines connected to each terminal device are once housed in the terminal device,
These terminal devices will be connected to each other. Therefore, when it becomes necessary to reconfigure the loop, it can be dealt with by simply reconnecting the corresponding transmission line in the terminal device. That is, it is possible to eliminate the need for civil engineering work for re-installing the transmission path. Therefore, even if the system has a service area in a congested area such as a downtown area or an urban area, the loop can be reconfigured extremely easily, in a short time, and at a low cost, which results in high flexibility. It becomes possible to provide the system.

Further, if the two pairs of transmission lines leading from each terminal device to the terminal device are laid on mutually different routes, even if one of the two pairs of transmission lines is disconnected due to, for example, an earthquake or an accident. , The communication can be continued using the other transmission path, and the probability of system down can be reduced.

Further, when an existing circuit switching network exists, a large-scale construction is required when a loop is newly constructed or added by using the switching station and the line equipment of this circuit switching network. There is an advantage that a new loop can be constructed relatively easily.

[0015]

EXAMPLES The present invention will be described below with reference to examples.

FIG. 1 is a schematic configuration diagram of a loop transmission network system in an embodiment of the present invention. In addition,
In this embodiment, a case where a loop transmission network is constructed by using eight terminal devices will be described as an example.

In the figure, DT1 to DT8 are terminal devices such as data terminals and facsimile devices owned by the subscribers, and these terminal devices DT1 to DT8 are respectively terminal connection devices CN1 to CN1 installed in the subscriber's home. CN8
Connected to. Each of these terminal connection devices CN1 to CN8 performs loop transmission control with a terminal connection device of another communication partner during communication, and also performs optical-electric conversion and electric-optical conversion of transmission information with the terminal device. Converting.

By the way, the system of this embodiment is equipped with a terminal device TM. This terminal device TM is
For example, it is installed in an exchange station ST already provided for constructing a circuit switching network. The terminal device TM includes an input side terminal board IB and an output side terminal board OB as shown in FIG. 2, and these terminal boards IB, O are provided.
B has a plurality of optical input connector terminals IT0 to IT, respectively.
8 and optical output connector terminals OT0 to OT8 are provided.

An inter-loop connecting device LCN1 is installed in the switching center ST. This loop connection device LC
N1 is for connecting the loop transmission network to another loop transmission network (not shown), and its input transmission line ILN0 and output transmission line OLN0 are respectively the input side terminal board IB and output side of the terminal device TM. It is connected to the optical input connector terminal IT0 and the optical output connector terminal OT0 arranged on the side terminal board OB.

On the other hand, the above-mentioned terminal connection devices CN1 to CN8
The input transmission lines ILN1 to ILN8 and the output transmission lines OLN1 to OLN8 respectively connected to are passed through an existing conduit for a circuit switching network buried under a public road, for example, and are connected to the terminals in the switching center ST. It is led to the device TM. The input transmission lines ILN1 to ILN8 and the output transmission lines OLN1 to OLN8 are respectively connected to the optical input connector terminals IT1 to IT1 arranged on the input side terminal board IB and the output side terminal board OB of the terminal device TM as shown in FIG. I
T8 and optical output connector terminals OT1 to OT8.

Each optical input connector terminal IT0-I
A connecting optical fiber CB in which optical connector terminals are mounted on both ends between T8 and the optical output connector terminals OT0 to OT8.
0 to CB8 selectively connect. The connection of the connecting optical fibers CB0 to CB8 is performed manually by the operator. Thus, in the service area centering on the switching center ST, a loop transmission network system is constructed in which eight terminal connection devices CN1 to CN8 and the inter-loop connection device LCN1 are connected in a loop by an optical transmission line.

Since there is such a system, when it becomes necessary to reconfigure the loop due to the introduction of a new technology having a different protocol, for example, the optical input connector terminals IT0 to IT8 and the optical output connector in the terminal device TM. The loop can be reconfigured by appropriately changing the connection between the terminals OT0 to OT8.

For example, when the loop transmission network configured as shown in FIG. 1 is divided into two independent loop transmission networks having different loop transmission systems as shown in FIG. 3, first, the terminal device TM is looped. An inter-connector LCN2 is added, and an optical input connector terminal IT9 and an optical output connector terminal OT9 for connecting the loop inter-connector LCN2 to the input terminal board IB and the output terminal board OB, respectively. Then, in the terminal device TM, each of the optical input connector terminals IT0 to IT depending on the configuration of the two loop transmission networks.
9 and the optical output connector terminals OT0 to OT9 are reconnected by connecting optical fibers CB0 to CB9. Figure 4
Shows the state after the connection.

In this way, according to the system of this embodiment, the terminal connection devices CN1 to CN8 and the inter-loop connection device L are connected.
The output transmission lines OLN1 to OLN9 and the input transmission lines ILN1 to ILN9 of the CN1 and LCN2 are all accommodated in the terminal device TM, and in this terminal device TM, the output transmission lines OLN1 to OLN9 and the input transmission lines ILN1 to
Since the optical fibers CB0 to CB9 for connection are appropriately connected to the ILN9, the loop is reconfigured in the terminal device TM in the output transmission lines OLN1 to OLN.
9 and the input transmission paths ILN1 to ILN9 can be changed. Therefore, it is possible to completely eliminate the work of laying a new transmission line and the work of removing an unnecessary transmission line, which makes it possible to reconfigure the loop extremely easily, in a short time, and at a low cost.

Further, despite the loop transmission network, since all the transmission paths of the terminal connection devices CN1 to CN8 are all accommodated in the terminal device TM, for example, a failure such as a disconnection somewhere on the loop. When it occurs, the terminal section TM can monitor the signal of each transmission line to specify the faulty section easily and in a short time. For this reason, it becomes possible to start the work for recovering from the failure promptly.

Further, in this embodiment, the terminal device TM
Is installed in the switching center ST of the existing circuit switching network, and the transmission lines of the terminal connection devices CN1 to CN8 are the line facilities (underground pipelines) already installed to build the circuit switching network. Therefore, even when a loop transmission network is newly constructed or added, a system can be constructed extremely easily and in a short period of time without performing large-scale transmission line laying work.

The present invention is not limited to the above embodiment. For example, in the above embodiment, each terminal connection device C
The system has been described by taking N1 to CN8 as a loop connection with a pair of input / output transmission lines as an example. The invention may be applied. In this case, it is effective to make the laying routes of the two pairs of input / output transmission lines different from each other.

That is, in a system in which one transmission system is constructed by using two pairs of input / output transmission lines, for example, as shown in FIG.
nb, ILNb, and OLNa form transmission line pairs P1 and P2, respectively, and these transmission line pairs P1 and P2 are laid on different routes. In this way, if the transmission line pair P
Even if 1 is disconnected, the terminal connection device CN can continue to communicate with another terminal connection device by using the transmission lines LNa and LNb of the other transmission line pair P2.

In a system that uses two pairs of input / output transmission lines to form two independent transmission systems, for example, as shown in FIG. 6, the input / output transmission lines OLN of the same transmission system are used.
a, ILNa and OLNb, ILNb form transmission line pairs P1, P2, respectively, and these transmission line pairs P1, P1
Lay P2 on a different route. By doing so, even if one transmission system is disconnected, it is possible to continue the communication using the transmission line of the other transmission system.

That is, by making the laying routes of the transmission line pairs P1 and P2 appropriately set according to the system as described above, the two pairs of input lines are set when a failure such as a transmission line disconnection occurs. It is possible to prevent the output transmission line from being in a non-communication state at the same time, which enables communication to be continued using the other input / output transmission line. That is, it is possible to reduce the probability that the system will go down.

Further, the terminal device TM may be provided with a display device for detecting and displaying the transmission state of the signal for each transmission line. By doing so, for example, when a failure occurs on the loop, it is possible to immediately recognize the failure occurrence section by looking at the display.

Furthermore, the terminal device is provided with a changeover switch group for selectively changing over between each input transmission line and each output transmission line, and by this changeover switch group, each input transmission line and each output transmission line are connected. It may be configured to change the connection state between them.

Further, in the above embodiment, all the transmission lines of each terminal connecting device are guided to the terminal device TM.
For the terminal connection device that is not the target of loop reconfiguration, the input / output transmission line is directly connected to another adjacent terminal connection device without passing through the terminal device TM, and only the terminal connection device that is the target of loop reconfiguration is connected. The output transmission line may be guided to the terminal device TM and connected to the input / output transmission line of another terminal connection device.

Further, in a system having a bidirectional transmission line, a terminal device may be provided for each transmission line. Further, in the above-mentioned embodiment, the system using the optical fiber cable as the transmission line has been described as an example.
It can also be applied to a system using another transmission cable such as a coaxial cable. In addition, the number of installed terminal devices and terminal connection devices, the configuration of terminal devices, the number of installed devices, installation locations, and the like can be variously modified and implemented without departing from the scope of the present invention.

[0035]

As described in detail above, according to the present invention, a terminal device is installed in addition to a plurality of terminal devices each having a function for loop transmission and distributed and arranged at arbitrary positions. The input transmission line and the output transmission line respectively connected to the terminal device are guided to the terminal device, respectively, and in the terminal device, the input transmission line and the output transmission line are selectively connected to each other. A loop transmission network that passes through terminal devices is configured.

Therefore, according to the present invention, the reconfiguration of the loop can be performed extremely easily and in a short time without requiring a large-scale construction, thereby making the loop transmission network system inexpensive and rich in flexibility. Can be provided.

Further, according to the present invention, when the loop transmission network system is bidirectionally configured by using two pairs of transmission lines, the two pairs of transmission lines guided from each terminal device to the terminal device are different from each other. By laying on the route, it is possible to provide a loop transmission network system that can suppress the influence of a failure even if it occurs.

Further, according to the present invention, when an existing circuit switching network exists, the terminal device is installed in the switching center of the circuit switching network, and the input transmission line and the output transmission line of each terminal device are connected to the line. By laying at least part of the existing line equipment of the exchange network in common and guiding it to the above-mentioned terminal device, not only reconfiguration of the loop but also new construction and expansion of the loop can be easily performed. A loop transmission network system capable of being provided can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a loop transmission network system according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of the terminal device shown in FIG.

3 is a schematic configuration diagram showing an example of a configuration after loop reconfiguration of the system shown in FIG.

FIG. 4 is a schematic configuration diagram of the terminal device shown in FIG.

FIG. 5 is a diagram showing a main configuration of a loop transmission network system according to another embodiment of the present invention.

FIG. 6 is a diagram showing a main configuration of a loop transmission network system according to another different embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing an example of a conventional loop transmission network system.

8 is a diagram showing an example of a configuration after loop reconfiguration of the system shown in FIG.

[Explanation of symbols]

DT1 to DT8 ... Terminal equipment, CN1 to CN8 ... Terminal connecting device, ST ... Exchange station, LCN1, LCN2 ... Loop connecting device, TM ... Terminal device, IB ... Incoming terminal board, O
B ... Output side terminal board, IT0-IT9 ... Optical input connector terminal, OT0-OT9 ... Optical output connector terminal, ILN0-
ILN9 ... Input transmission line, OLN0-OLN9 ... Output transmission line, CB0-CB9 ... Optical fiber for connection.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kotaro Yamaguchi 1-34 Roppongi, Minato-ku, Tokyo NTay Internacional Co., Ltd.

Claims (3)

[Claims] 1. A plurality of terminal devices each having a function for loop transmission and distributed and arranged at arbitrary positions, and terminal devices installed separately from these terminal devices are provided. Each of the input transmission lines and the output transmission lines connected to the terminal device is guided to the terminal device, and in the terminal device, the input transmission lines and the output transmission lines are selectively connected to each other, thereby A loop transmission network system characterized in that a loop transmission network passing through a terminal device is configured. 2. When a two-way transmission path is used to construct a bidirectional loop transmission network that passes through a plurality of terminal devices, each terminal device leads to a terminal device.
The loop transmission network system according to claim 1, wherein the pair of transmission lines are laid on mutually different routes. 3. When an existing circuit-switched network exists, a terminal device is installed in a switching center of the circuit-switched network, and an input transmission line and an output transmission line of each terminal device are installed in the existing circuit-switched network. The loop transmission network system according to claim 1, wherein at least a part of the line equipment is shared and laid and guided to the terminal device.