JPH04160845A - Communication network system and communication station equipment - Google Patents

Abstract

PURPOSE:To prevent occurrence of a fault or the like in a path protection switch itself by selecting a normal data among data sent via each transmission line, outputting the data from a relevant reception section and integrating the data and outputting the result to one system of data bus. CONSTITUTION:A 2nd communication station RX is provided with data selection sections 51-53 provided in relation with each of plural transmission lines OT1-3 and a coupling section 60 comprising a passive element in a communication network system in which a 1st communication station TX branches a transmission data to plural same data and sends them in parallel to the 2nd communication station RX via the plural transmission lines OT1-3. Then the data selection sections 51-53 select one normal data among sent data according to a prescribed selection algorithm, output the data from a relevant reception section and the data are integrated by the coupling section 60 and the result is outputted to one system data bus. Thus, the occurrence of a fault or the like in a path protection switch itself is prevented and the reliability of the system is enhanced.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a communication network system constructed for inter-office transmission in a public line network, and a communication station device used in this system. Regarding.

(Prior Art) In recent years, a system employing a parallel transmission/reception switching method has been proposed as a communication network system used for inter-office transmission in a public line network. In this type of system, when transmitting data from a transmitting station to a receiving station, the transmitting station branches the transmitted data to generate multiple pieces of identical data, and then divides these data into multiple different pieces of data. Each signal is transmitted in parallel to the receiving station via the transmission path. The receiving station selects one correct piece of data as a received signal from among the pieces of data transmitted in parallel through each of the transmission lines. Such a system can perform data transmission with higher reliability than a system that transmits data through a single transmission path.

(Problem to be solved by the invention) However, this type of system that has been considered in the past uses a relay or semiconductor switch in order to select the correct data from among multiple data at the receiving station. A bus protection switch consisting of an active element is provided, and by switching this switch, one correct piece of data is selected and output. For this reason, there were problems to be improved as follows. That is, since the bus protection switch is an active element, failures may occur by itself, and the data of the entire transmission system is intensively switched and outputted by one bus protection switch. Therefore, if a failure occurs in the bus protection switch,
This could lead to instant system downtime, making the system unreliable.

Therefore, the present invention has focused on the above-mentioned circumstances, and aims to provide a communication network system and a communication station device that can prevent failures and the like from occurring in the bus protection switch itself, thereby increasing the reliability of the system.

[Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the communication network system of the present invention branches transmission data into a plurality of identical data at a first communication station and divides these data into multiple pieces of data. are transmitted in parallel to a second communication station via multiple transmission lines, and the second communication station selectively selects appropriate data from among the data transmitted via the plurality of transmission lines. In the communication network system to be selected, the second communication station includes a data selection section having a plurality of reception sections provided corresponding to each of the plurality of transmission paths, and a coupling section made of a passive element. Then, the data selection section selects one normal piece of data from among the data transmitted via each of the transmission paths according to a predetermined selection algorithm, and transmits this selected data from the corresponding reception section. The data output from these receivers is integrated by the above-mentioned combiner and 1
It is designed to output to the system data bus.

On the other hand, the communication station device of the present invention includes a data selection section having a plurality of reception sections provided corresponding to each of a plurality of transmission paths, and a coupling section made of a passive element, and the data selection section allows One piece of normal data is selected according to a predetermined selection algorithm from among the data transmitted via each of the transmission paths, and this selected data is output from the corresponding receiving section, and the plurality of data The data output from the receiving section is integrated by the coupling section and output to one system of data buses.

Further, in the communication station device of the present invention, the data selection unit assigns priorities for selecting data to a plurality of reception units, and operates each of the reception units in order according to this priority order, thereby selecting the correct one. It is also characterized by being configured to output data.

Further, in the communication station device of the present invention, the data selection unit is configured to select and output one correct piece of optical data from the width of each piece of optical data transmitted via the plurality of optical transmission lines from the transmitting side. and the coupling section integrates the optical data output from the data selection section using an optical star coupler.
It is also characterized by being configured to output to the optical transmission line of the system.

(Function) As a result, according to the present invention, since the bus protection switch is constituted by a coupling section composed of passive elements, there is no fear that the bus protection switch itself will malfunction. Since the data selection operation is performed for each transmission path, the risk of failure of the receiving section is dispersed. Therefore, the occurrence of a problem in which a failure of one circuit section on the receiving station side immediately causes the system to go down is reduced, thereby making it possible to improve the reliability of the system.

(Embodiment) FIG. 1 is a schematic configuration diagram of a communication network system in an embodiment of the present invention.

This system includes a communication station device TX and a communication station device RX, and three optical transmission lines OT1, OT2, OT1, OT2, OT1, OT2, OT1, OT2, OT1, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT2, OT2, OT1, OT2, OT2, OT2, OT1, OT2, OT2, OT2, OT1, OT2, OT2, OT2, OT1, OT2, OT2, OT2, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT1, OT2, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT2, OT1, OT2, OT1, OT2, OT2, OT2, OT1, OT2, OT; Connected by OT3. These optical transmission lines OTI, OT2. O.T.
3 uses an optical fiber cable, and when the transmission distance is long, at least one optical repeater is inserted in the middle. Although FIG. 1 only shows the transmission system from the communication station apparatus TX to the communication station apparatus RX for convenience of explanation, in reality, a transmission system from the communication station apparatus RX to the communication station apparatus TX is also provided. This allows bidirectional inter-office data transmission.

The communication station device TX includes an optical star coupler 1 as a branching element.
0, optical transmission lines OTI, OT2. Three interface devices (ITF) 21 to 23 provided corresponding to OT3
and optical multiplex transmission equipment (OLTM) 31 to 33. In the optical star coupler 10, the optical transmission data TD is branched into three, and each of these branched optical transmission data is
It is supplied to TF21-23. These ITF21-2
In step 3, the supplied optical transmission data is converted into electrical signals, and the transmission data made up of these electrical signals are supplied to the OLTMs 31 to 33, respectively. OLTM31~33
each has multiple input ports, and the above IT
time-division multiplexing of the transmission data supplied from F21 to F23 with transmission data supplied from other ITFs (not shown);
This time-division multiplexed data is converted into optical signals and optical transmission line OT
Send to 1 to OT3.

On the other hand, the communication station device RX includes optical multiplex transmission devices (OLTM) 41 to 43 provided corresponding to the optical transmission lines OT1 to OT3.
, interface devices (ITF) 51 to 53, and an optical star coupler 60. The OLTMs 41 to 43 convert time-division multiplexed data transmitted via the corresponding optical transmission lines OTI to OT3 into electrical signals, and further decompose the data into a plurality of low-speed transmission data to the corresponding ITFs 51 to 53.
supply to. In addition, the OLTMs 41 to 43 have a function to detect whether or not the transmitted data has been received correctly, and if the transmitted data is not received correctly, the low-speed transmitted data is sent as an alarm display signal (AIS). signal)
Replace with and output.

The ITFs 51 to 53 are configured as follows, for example. Second
The figure is a circuit block diagram showing its configuration. That is,
The ITFs 51 to 53 have detection circuits 71 to 73, respectively, and
It has receiving circuits 81 to 83.

The detection circuits 71-73 each have means for detecting whether correct transmission data is supplied from the OLTMs 41-42. In this detection means, detection is performed, for example, by the following method. That is, OLTM
41 to 43, whether or not transmission data is supplied, whether or not the supplied transmission data is an AIS signal, and whether an error correction operation is performed on the transmission data and an error of a predetermined amount or more is detected. It will be judged. As a result of these determinations, if some transmission data is input, this transmission data is not an AIS signal, and the error is less than a predetermined amount, it is recognized that correct transmission data has been supplied. On the other hand, if the above conditions are not met, it is determined that correct transmission data has not been transmitted.

Furthermore, the priority order of detection operations is determined in advance for each of the detection circuits 71 to 73. For example, the detection circuit 71 is assigned the first priority, the detection circuit 72 is assigned the second priority, and the detection circuit 73 is assigned the third priority.

The detection circuits 71 and 72 sequentially perform the detection operations according to the priority order. When it is detected that correct transmission data has been supplied during its own detection operation, operation permission signals SCI and SC2 are sent to the corresponding receiving circuits 81 to 83.
supply. If correct transmission data is not detected, operation command signals SSI and SS2 are supplied to the detection circuit with the next highest priority to cause it to perform a detection operation.

The receiving circuits 81 to 83 are normally in a non-operating state, and receive an operation permission signal S from the corresponding detection circuits 71 to 73.
It becomes operational only when CI to SC3 are supplied. Then, in this operating state, the transmission data supplied from the detection circuits 71 to 73 is converted into an optical signal, and this optical transmission data is output to the optical star coupler 60.

The optical star coupler 60 has at least three input ports and one output port, and each of the receiving circuits 81
It mixes and integrates the optical transmission data outputted from ~83, and outputs it from an output port.

Next, the operation of the system configured as above will be explained. In the communication station device TX, the transmission data TD is branched into three by the optical star coupler 10 and input to ITFs 21 to 23. The signals are converted into electrical signals by these ITFs 21 to 23 and then introduced to the OLTMs 31 to 33. In these OLTMs 31 to 33, the transmission data supplied from the ITFs 21 to 23 is time-division multiplexed together with transmission data supplied from other ITFs (not shown), and then converted into optical signals and sent to the optical transmission lines OT1 to OT3. will be sent to. That is, one system of transmission data is transmitted in parallel through three systems of optical transmission lines.

On the other hand, the communication station device RX performs the following operation. That is, when time-division multiplexed data arrives via optical transmission lines OTI to OT3, this time-division multiplexed data is first converted into electrical signals by the OLTMs 41 to 43, and then decomposed into a plurality of low-speed transmission data. It is determined whether the data is correct or not for each low-speed transmission data.

If it is determined to be correct, the transmission data is output as is to the corresponding ITF 51-53, whereas if it is determined to be incorrect, the transmission data is replaced with an AIS signal and output to the corresponding ITF 51-53.

Now, in the ITFs 51 to 53, the detection circuit 71 having the highest priority among the detection circuits 71 to 73 operates first.

This detection circuit 71 determines whether transmission data is supplied from the OLTM 41 and whether the supplied transmission data is
It is determined whether the signal is an S signal or not, and whether an error correction operation is performed on the transmitted data and a predetermined amount or more of errors are detected. If, for example, some transmission data is input and it is determined that this transmission data is not an AIS signal and that the error is less than a predetermined amount, it is recognized that correct transmission data has been supplied, and the detection circuit 71
An operation permission signal SCI is output from the receiving circuit 81 to the corresponding receiving circuit 81. Then, the reception circuit 81 becomes operational, and as a result, the transmission data supplied from the detection circuit 71 is converted into an optical signal and output to the optical star coupler 60. The transmission data then passes through the optical star coupler 60 and is output as received data to a subsequent circuit.

On the other hand, suppose that the detection circuit 71 detects that no transmission data is transferred from the OLTM 41, that an AIS signal is detected, or that data errors exceed a predetermined amount. Then, the detection circuit 71 does not output the operation permission signal SCI to the reception circuit 81, but instead outputs the operation command signal CCI to the detection circuit 72 having the next highest priority. Therefore, the detection circuit 72 is brought into operation instead, and the detection circuit 72 determines whether or not correct transmission data has been supplied from the OLTM 42.

When it is determined that correct data has been supplied, the detection circuit 72 outputs an operation permission signal SC2 to the corresponding receiving circuit 82, and as a result, the receiving circuit 82 enters the operating state. Therefore, the transmission data outputted from the detection circuit 72 is converted into an optical signal by this receiving circuit 82 and then outputted to the optical star coupler 60.
0 to the subsequent stage circuit as received data RD.

On the other hand, if the detection circuit 72 does not detect the supply of correct transmission data, the detection circuit 72
An operation instruction signal SS2 is output from the detection circuit 73 to the detection circuit 73. Therefore, the detection circuit 73 is now in an operating state, and the detection circuit 73 detects whether or not the transmission data has been correctly supplied from the OLTM 43. When the detection circuit 73 detects the supply of correct transmission data, the detection circuit 73 sends an operation permission signal SC3 to the reception circuit 83.
is output. As a result, the receiving circuit 83 becomes operational, whereby the transmission data outputted from the detection circuit 73 is converted into an optical signal and outputted to the optical star coupler 60, and further transmitted to the subsequent stage circuit via the optical star coupler 60. Output.

Note that if the supply of correct transmission data is not detected even in the detection circuit 73 having the lowest priority, for example, the detection circuit 73 having the highest priority is returned to and the same detection operation is repeated again, or the detection circuit 73 The receiving circuit corresponding to any one of 71 to 73 is activated, and the AIS signal is outputted to the subsequent circuit via this receiving circuit and the optical star coupler 60.

In this way, in this embodiment, since the optical star coupler 60 made of passive elements is used as the bus protection switch of the communication station equipment RX on the receiving side, there is no need to worry about failure occurring in the optical star coupler 60. . Further, selection of the transmission data sent through each of the optical transmission lines OTI to OT3 is performed by ITFs 51 to 53 provided for each of the optical transmission lines OTI to OT3, respectively. In other words, the selection of transmission data is not performed by switching with a switch, but by selectively operating the ITFs 51 to 53 according to the priority order, and autonomously permitting or prohibiting the output of the transmission data. It is done. Therefore, unless all three ITFs 51 to 53 fail at the same time, the transmission data selection operation will be performed.
The reliability of the system and communication station equipment can be improved compared to the case where selection is made using two changeover switches.

Furthermore, as a recent system trend, consideration is being given to using a synchronous digital hierarchy (SDR) as an in-office interface. In the case of such a system, it is difficult to use an electric switch, but by using the optical star coupler 60 as in this embodiment, it becomes easy to accommodate the above-mentioned native needs.

Note that the present invention is not limited to the above embodiments. For example, in the detection circuits 72 and 73, even if a certain period of time has elapsed since the data arrived, the detection circuit 71 with a high priority
．． If neither an operation request signal nor an operation instruction signal is output from 72, it is determined that there is a possibility that a higher priority detection circuit is out of order, and the data selection operation is automatically started. You can. In this way, even if a detection circuit with a higher priority becomes completely inoperable, other detection circuits can perform data selection operations, thereby ensuring high system reliability.

Further, the priority order may be automatically changed periodically or irregularly, and the priority order may be given to each detection circuit at random. As a result, the data selection operation is concentrated in a small number of fixed detection circuits, thereby reducing the problem that these detection circuits are prone to failure.

Furthermore, in the above embodiment, a priority is set for each of the three ITFs 51 to 53, and each ITF 51 is set according to this priority.
Although the ITFs 51 to 53 are configured to perform operations for selecting transmission data, each ITF 51 to 53 operates in parallel without setting a priority order, and the correct transmission data is selected only from the ITF that detected it earliest. may be configured so that it is output.

Furthermore, in the embodiment described above, each of the ITFs 51 to 53 was configured to operate autonomously according to the priority order, but each ITF
A control unit is provided to centrally manage the F, and this control unit controls each I
The TF may also be controlled.

Furthermore, in the above embodiment, a system was described in which data is transmitted using an optical transmission line and data is branched and combined using an optical star coupler within the communication station equipment. The present invention may be applied to a system that uses a transmission line and uses electrical branching circuits and combining circuits in communication station equipment to branch and combine data.

In addition, we also discuss the number of transmission lines, the configuration of ITF, the type and configuration of coupling parts consisting of passive elements, and the configuration of the selection algorithm for selecting one normal data from among the data transmitted by multiple transmission systems. However, various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As described above in detail, the communication network system and communication station device of the present invention include a data selection unit having a plurality of receiving units provided in the communication station device corresponding to each of a plurality of transmission paths. and a coupling section consisting of a passive element, and the data selection section selects one normal piece of data from among the data transmitted via each of the transmission paths according to a predetermined selection algorithm. The received data is output from the corresponding receiving sections, and the data output from these receiving sections are integrated by the coupling section and output to one system of data buses.

Therefore, according to the present invention, it is possible to prevent failures and the like from occurring in the bus protection switch itself.
Thereby, it is possible to provide a communication network system and a communication station device that can improve system reliability.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a communication network system according to an embodiment of the present invention, and FIG. 2 is a circuit block diagram showing the configuration of a main part of a communication station device on the receiving side of the system. TX, RX... Communication station equipment, OTI to OT3... Optical transmission line, 10... Optical star coupler for data branching, 2
1-23...transmission interface device, 31-3
3... Optical multiplex transmission device for transmission, 41-43... Optical multiplex transmission device for reception, 51-53... Interface device for reception, 60... Optical star coupler for data synthesis, 71-73...Detection circuit, 81-83...Reception circuit, SC1-SC3...Operation permission signal, SSI,
SS2...Operation instruction signal. Applicant's agent Patent attorney Takehiko Suzue

Claims (4)

[Claims] (1) The first communication station branches the transmission data into multiple pieces of identical data and sends these data to the second station via multiple transmission paths.
In the communication network system, the second communication station selectively selects appropriate data from among the respective data transmitted via the plurality of transmission paths. The communication station has a plurality of receiving units provided corresponding to each of the plurality of transmission paths, and selects a normal one from among each data transmitted via each of the transmission paths according to a predetermined selection algorithm. a data selection section that selects one piece of data and outputs the selected data from the corresponding receiving section; and a passive element that integrates the data output from the plurality of receiving sections and outputs it to one data bus. What is claimed is: 1. A communication network system comprising: a coupling section; (2) In a communication station device that receives a plurality of identical data transmitted in parallel from a transmitting side via a plurality of transmission paths, and selects and uses appropriate data from among these data, It has a plurality of receiving sections provided corresponding to each of the transmission paths, and selects one normal piece of data from among each data transmitted via each transmission path according to a predetermined selection algorithm. A data selection section that outputs selected data from the corresponding receiving section; and a coupling section that includes a passive element that integrates the data output from the plurality of receiving sections and outputs it to one data bus system. A communication station device characterized by: (3) The data selection section is characterized in that it assigns priorities for selecting data to a plurality of reception sections, and outputs one correct piece of data by operating each of the reception sections in order according to the priority order. The communication station device according to claim (2). (4) The data selection section selects and outputs one correct piece of optical data from among the respective optical data transmitted via the plurality of optical transmission lines from the transmission side, and the coupling section selects and outputs one correct piece of optical data from the respective optical data transmitted from the transmission side via the plurality of optical transmission lines, and the coupling section 3. The communication station apparatus according to claim 2, wherein the output optical data is integrated by an optical star coupler and outputted to one optical transmission line.