JPH0548628A - Loop communication system - Google Patents

Abstract

PURPOSE:To obtain the service of a faulty digital exchange for a terminal equipment connecting to a remote unit even when the fault takes place in a station or the digital exchange by connecting at least two sets of digital exchanges and line concentrators or over in duplicate. CONSTITUTION:In order to countermeasure a fault of a station or a digital exchange DSN in stations ST1, ST2, they have the digital exchanges DSN and line concentrators CON in duplicate and in cross connection. Thus, the line concentrator CON and the digital exchange DSN (system 1) of the station ST1 are used for the active system (the system used at first) and the line concentrator CON and the digital exchange DSN (system 0) of the station ST2 are used for the standby system. Thus, when a fault takes place, the line concentrator CON and the digital exchange DSN (system 1) are replaced with the line concentrator CON and the digital exchange DSN (system 0) of the standby system of the station ST2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loop type communication system of circuit switching equipment for providing a part of services of a digital exchange by a local area network.

[0002]

2. Description of the Related Art Due to the establishment of ISDN technology, digital exchanges are not limited to telephone line exchanges, but also low-speed terminals, TV telephones, and G4FAX connections and services that enable high-detail and fast transmission of documents, etc. It is possible to provide file transfer / moving image transfer services and the like using a wide band of 5 Mbps.

[0003] The digital exchange provides various exchange services in intelligent buildings and hotels, as well as services such as pocket telephones in hospitals, and has various usage forms and requirements. In recent years, local area networks (LANs) have been applied with optical technology at 100 Mbps, 400
Those having a speed of Mbps have been announced by various companies.
FIG. 3 shows an example of a new architecture of a complex information communication system combining a high-speed optical LAN and a digital exchange.

That is, in contrast to a conventional system in which one large-capacity digital exchange leaves all the functions of the exchange, the digital exchange is housed in a LAN station and the LAN is used as a transmission line between the digital exchanges. , The functions of each digital exchange are distributed.

However, installing many digital exchanges in one building and newly installing the digital exchanges on a floor with a small number of extension leads to consideration of the installation site and an increase in system cost.

For this reason, a shelf that can accommodate a large number of circuit switching terminals in remote locations (hereinafter referred to as a remote unit)
As shown in FIG. 4, the optical loop LAN station is accommodated by a digital high-speed line, and the function of the digital exchange is used to provide the service of the digital exchange to the terminal interface of the remote unit (remote unit).
A large number of interfaces such as ISDN, analog telephone, digital telephone, and V24 terminal used in the digital exchange can be connected to this remote unit.

However, if the optical loop station or the digital exchange fails, there is a problem that the service of the digital exchange cannot be provided to the terminal connected to the remote unit.

[0008]

As described above, in the conventional communication system, when the station of the optical loop or the digital exchange fails, the service of the digital exchange cannot be provided to the terminal connected to the remote unit. There was a problem.

The present invention has been made in view of the above circumstances, and in order to cope with a failure of a station or a digital exchange, at least two or more digital exchanges and a concentrator are dually connected and connected. An object of the present invention is to provide a loop communication system capable of providing a service of a digital exchange to a terminal connected to a remote unit even when a failure occurs in a station or a digital exchange.

[0010]

In the loop communication system of the present invention, a plurality of stations are connected in a loop by a transmission line, and the plurality of stations and a plurality of digital exchanges are multi-membered. A means for connecting and setting one for active use and the other for standby, a remote unit provided in the plurality of stations and accommodating the external terminal interface of the digital exchange, to which a plurality of terminals are connected, to this remote unit A first processing means for providing a service utilizing the switching function of the active digital exchange to a plurality of connected terminals, and a standby station or a digital standby station when the active station or the digital exchange fails. It is composed of a second processing means for performing an exchange process using an exchange.

[0011]

According to the present invention, in a case where a plurality of stations are connected in a loop by a transmission line, the plurality of stations and a plurality of digital exchanges are connected in multiple association, one of them being in use and the other being in standby. When the current station or the digital exchange fails, the standby station or the digital exchange is used to perform the exchange process.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a loop communication system of the present invention.

In the loop communication system shown in FIG. 1, a plurality of stations ST1, ST2, ... Are connected in a loop via a transmission line F composed of, for example, an optical fiber. A concentrator CON is housed in each of the stations ST1 ,. The concentrator CON accommodates a shelf (remote unit) RU that accommodates an external terminal interface of the digital exchange DSN. Concentrators CON of the stations ST1, ...
A terminal T, ... Or a digital exchange DSN is connected to.

For example, stations ST1 and ST2 are connected to a digital exchange DSN (1 system, 0 system), respectively, and stations ST3 and ST4 are connected to terminals T, ... Through a remote unit RU.

In the stations ST1 and ST2, the digital exchange and the concentrator are doubly attributed and connected in order to cope with a failure of the station or the digital exchange, and the concentrator CON and the digital of the station ST1 are connected. The switching equipment DSN (1 system) is used as the current one (the first equipment side used), and the concentrator CON of the station ST2 and the digital switching equipment DSN are used.
(0 system) is used for standby. As a result, when a failure occurs, by switching to the standby digital exchange (system 0) and the concentrator CON of the station ST2, it is possible to prevent the system from going down. The terminals T, ... Are, for example, personal computers and facsimiles (FAX).
Etc.

FIG. 2 is a diagram showing an example of a frame format used in communication of the loop communication system (time division multiplexing system) shown in FIG. The data communication speed is 2.048 Mbps. 3 in 64 Kbps units
There are two channels, and each channel carries call data or control data. By using a certain channel as an identification of the data currently being transmitted, that is, an identification of control data or call data, it becomes possible to perform exchange in the digital exchange DSN.

As a result, the exchange of the communication channel in units of 64 Kbps is realized for each communication data channel (between the remote unit RU and the digital exchange DSN).
The services of the digital exchange DSN can be used by the terminals T, ... Connected to the external terminal interface of the remote unit RU which is remote.

The number of channels in one frame of the digital line does not have to be 32, and if it is 64 or more, the number of communication channels that can be handled at one time increases. At this time, the speed of the digital line interface of the concentrator CON and the digital exchange DSN is also increased.

The digital high-speed line data from the concentrators CON of the stations ST3 and ST4 are time-division multiplexed at the stations ST3 and ST4, respectively, and are connected to the digital exchange DSN (1 system) via the transmission line F. It is transmitted to the concentrator CON of the station ST1 which is being operated. The data is transmitted to the digital exchange DSN (1 system).

As a result, the digital exchange DSN (1
The service of the digital exchange DSN (1 system) is provided to the terminals T, ... Connected to the external terminal interface in the remote unit RU of the remote location (stations ST3 and ST4) using the exchange / service function of the system). ..

At this time, another digital exchange DSN (system 0) is connected to the station ST2 in order to cope with a failure of the station ST1 or the digital exchange DSN (system 1).

As a result, when a failure occurs in the station ST1 or the digital exchange DSN (1 system),
The data of the digital high-speed line from the concentrators CON of the stations ST3 and ST4 are time-division multiplexed at the stations ST3 and ST4, respectively, and the digital exchange DSN (system 0) is connected via the transmission line F. It is transmitted to the concentrator CON of the station ST2. The data is transmitted to the digital exchange DSN (0 system).

As a result, the digital exchange DSN (0
The service of the digital exchange DSN (system 0) is provided to the terminals T, ... Connected to the external terminal interface in the remote unit RU of the remote location (stations ST3 and ST4) by using the exchange / service function of the system (system). ..

As described above, by using the remote unit, it is not necessary to consider the installation place and increase the system cost, and it is not necessary to connect a large number of digital exchanges to the loop. In addition, it is possible to provide a digital exchange service to a terminal located in a remote place.

In addition, at least two or more digital exchanges and the concentrator are connected to each other by double assignment in order to cope with a failure of the station or the digital exchange. One of the digital exchange and the concentrator is used as the current one, the other is used as the standby, and in the case of a failure, switching to the standby exchange and the concentrator has the effect of preventing the system from going down. ..

[0026]

As described above in detail, according to the present invention, at least two or more digital exchanges and concentrators are double-assigned and connected to cope with a failure of a station or a digital exchange. Therefore, even if a failure occurs in the station or the digital exchange, it is possible to provide the loop communication system capable of providing the service of the digital exchange to the terminal connected to the remote unit.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a loop communication system of the present invention.

FIG. 2 is a diagram showing an example of a format of a frame communicated in FIG.

FIG. 3 is a diagram schematically showing a configuration of a complex information communication system.

FIG. 4 is a diagram schematically showing a configuration of an optical loop LAN.

[Explanation of symbols]

ST1, ... station, DSN, ... digital switch, RU, ... remote unit, CON, ... concentrator, T, ... terminal.

Claims (1)

[Claims] 1. In a loop communication system in which a plurality of stations are connected in a loop by a transmission line, the plurality of stations and a plurality of digital exchanges are connected in multiple association, one of them is in use and the other is on standby. And a remote unit that is provided in the plurality of stations and that accommodates the external terminal interface of the digital exchange and that is connected to a plurality of terminals, and a plurality of terminals that are connected to the remote unit. On the other hand, the first processing means for providing a service utilizing the exchange function of the current digital exchange and the standby station or the digital exchange perform the exchange processing when the current station or the digital exchange fails. A loop communication system comprising: a second processing unit.