JP3227857B2 - Data transmission method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission system, and more particularly to a data transmission system for a bidirectional loop type LAN.

[0002]

2. Description of the Related Art Conventionally, in a loop type LAN, communication between a plurality of terminal devices connected to a node device is performed by the node device allocating a communication line to a transmission line, and the node device is allocated to the communication line. A terminal device is connected to perform communication. The connected pair of communication lines is used only for communication between terminal devices at both ends, and cannot communicate with other terminal devices. That is, since a plurality of terminal devices commonly use one communication line, only one pair of communication can be performed at the same time. On the other hand, in the case of one-to-one communication in which a specific terminal device is connected and communicated one-to-one, a communication line separately allocated for this purpose is used. Communication line is required. For this purpose, a plurality of communication lines are obtained by time division multiplexing of a transmission line.

[0003]

As described above, according to the conventional method, when one m-to-m communication and n one-to-one communication between terminal devices via a node device are simultaneously performed, each of the communication methods is performed. It requires a plurality of communication lines allocated to a transmission path used for communication. In particular, when performing n one-to-one communication, n communication lines are required, and according to the total capacity of the transmission lines,
There is a problem that the number is limited.

[0004]

A data transmission method according to the present invention is a bidirectional loop type LAN in which 2n + 1 (n is a positive integer) node devices are connected in a ring by two communication lines.
A first terminal device is connected to each of the node devices, and an arbitrary pair of the first terminal devices communicate sequentially using a first communication band of the loop type LAN.
(M ≦ 2n + 1) When any one of the node devices is set as the first, the second terminal device is connected to each of the even-numbered node devices, and at the same time, the common terminal is connected to the odd-numbered node devices. A third terminal device is connected to each switching output of the line switching device for connecting a line switching device and selecting one of the connected odd-numbered node devices, and multiplexing is performed on the first communication band. A maximum of n pairs of one-to-one communication means for performing one-to-one communication between the second terminal device and the corresponding third terminal device using the second communication band I have.

Further, the line switching device inputs the transmission line operation state information of the loop type LAN from each of the odd-numbered node devices, and transmits a transmission data signal from the third terminal device and the second terminal device opposite thereto. Switching is performed by determining which of the adjacent odd-numbered node devices receives signals from the devices.

In addition, the loop type LAN further multiplexes a third communication band with the first and second communication bands and uses a new one similar to the one-to-one communication means using the third communication band. One-to-one communication means may be provided.

[0007]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a system configuration according to an embodiment of the present invention. In this figure, seven node devices 11 to 17 are connected in a loop in a doubly
7 to 7 communication is performed between any pair of terminal devices among the terminal devices 1 to 27, and the terminal devices 31 and 41, 32 and 42, 33 and 43
, Three one-to-one communications are performed. Terminal devices 31 and 3 are connected to even-numbered node devices 12, 14 and 16.
2, 33 signal lines are connected, and odd-numbered node devices 1
The signal lines 81 to 84 from 1, 13, 15, and 17 and the signal lines 71 to 74 for transmitting information on which system is operated in each node device are connected to the line switching device 50, and line switching is performed. The device 50 includes terminal devices 41, 42, 4
3 signal lines are connected.

FIG. 2 is a block diagram showing the configuration of the line switching device 50. A select signal generation circuit 51 that generates a select signal from operation system information of the node device transmitted from the signal lines 71 to 74 connected to the line switching device 50;
The selector circuits 52, 53, and 54 switch the path of the transmission line based on the select signal and include input / output ports B1, B2, and B3 that connect the communication lines on the node device side and the terminal device side.

In FIG. 1, node devices 11 to 17 are:
The transmission lines are connected in a loop by two transmission lines 61 to 67 each having a transmission capacity of 150 Mbps and a system 0 and a system 1. The communication line capacity required for communication between the terminal devices 31 and 41, 32 and 42, and 33 and 43 is 50
Mbps, the communication line capacity of the 7: 7 between the terminal devices 21, 22,... 27 is 100 Mbps, and the total is 250 Mbps.
The communication capacity of the communication line is enabled.

FIG. 3 shows a block diagram of the node device 11 as a representative example of the node device of FIG. Node device 11
Has a function of duplicating a loop, a loop bag function, a bypass function, a loop switching function, and the like. The main components are receiving circuits 111a to 111 that receive signals from a transmission path and generate a frame format of the transmission path.
b, Synchronization circuit 112 for synchronizing the whole loop and correcting delay
a, 112b, separation / separation for inputting / outputting data to / from a specific time slot having a frame format of a transmission line.
Coupling circuits 113a and 113b separating / combining circuits 113a,
Transmission circuits 115a and 115b for selecting the data from 113b or the data bypassed and looped back and transmitting the selected data to the transmission line, and separation / coupling circuits 113a and 113
b, a bus monitoring control circuit 115 for transmitting and receiving data from and via a bus, and a bus monitoring control circuit 115, various interface circuits 116 connected to the data bus and connectable to various external terminal devices, and monitoring and control of these circuits. And a monitoring / control circuit 114b.

These are completely duplicated except for a bus monitoring control circuit 115 and various interface circuits 116,
System and system 1 are distinguished from each other. Usually, one of the systems operates as an operation (ACT) system, and the other system operates as a standby system (STB).
Y), and the remaining system is the standby system (STBY system)
Works as If the system 0 is an ACT system, the main flow of the signal is the transmission line 61 of the system 0, the receiving circuit 111a, the synchronizing circuit 112a, the separating / coupling circuit 113a, and the transmitting circuit 11
5a and the transmission path 62 in that order.

On the other hand, the STBY system 1 is a transmission line 6
2, receiving circuit 111b, transmitting circuit 115b, transmission line 61
The bypass function operates in the order shown. Depending on conditions, the transmission path 61, the receiving circuit 111a, the synchronization circuit 112
a, a separation / coupling circuit 113a, a transmission circuit 115a, a 1-system transmission circuit 115b, and a loop-back function from 0-system 1 to 1-system serving as a 1-system transmission line 62 operates.

FIGS. 4A and 4B show the paths of the 7-to-7 communication line in FIG. 1, wherein FIG. 4A shows the case where the system 0 of the node device is in the ACT state, and FIG. 4B shows the case where the system 1 of the node device is in the ACT state. Shows the respective communication line paths.

Next, 1: 1 communication using the line switching device 50 will be described. As described above, 1 in 7 to 7 communication
Since the communication line capacity of 00 Mbps is used, the remaining communication line capacity of 50 Mbps can be used. The communication line capacity used for one set of one-to-one communication is 50M
Although this is bps, this embodiment uses three sets of one-to-one communication.

FIG. 5 shows that the ACT 0 of all the node devices is ACT.
The communication path in the case of the system is shown by a thick line. Terminal device 41
Is transmitted to the transmission line of system 0 by the node device 11 through the line switching device 50, and the transmission data of
2 to retrieve this data and receive it as terminal data 3
1 is output. On the other hand, the transmission data of the terminal device 31 is
The data of the terminal device 41 is sent to the transmission line by the node device 12 using the same communication circuit used when sending the data of the terminal device 41 to the terminal device 31, the data is received by the node device N 13, output to the line switching device 50, The line from the node device 13 is selected by the circuit 55 and output to the terminal device.
Similarly, communication between the terminal devices 32 and 42 and between the terminal devices 33 and 43 is also performed using the same communication line in common.

FIG. 6 shows the communication path when the system 1 is an ACT system by a thick line. This is also performed using a specific communication line in common as in FIG. The difference is that communication is performed on the transmission line of the system 1 and that the selection paths of all the selector circuits of the line switching device 50 are all opposite to those in the case of the ACT of the system 0.

FIG. 7 shows node devices 15 and 16
The communication path of the one-to-one communication when a loop in both systems has an abnormality between them is indicated by a thick line. Here, the case where the system 0 of the other node devices except the node devices 15 and 16 in which the loopback is performed is in the ACT state is shown. Node device 1
5 and the node device 16 detect a loop abnormality in both systems, and the loopback function operates. In FIG. 5, the terminal device 4
3 is transmitted from the node device N15 to the node device 1
6, but in FIG. 7,
Due to the loop failure, the transmission data from the terminal device 43 is returned to the transmission line of the first system by the node device 15 and is transmitted to the node node device 16 by bypassing the first system of the node devices 14, 13, 12, 11, and 17. Then, in the node device 16, the system 1 operates as the ACT system and data is sent to the terminal device 33. Similarly, terminal devices 31 and 41, 32 and 42
In both cases, a communication line is secured and communication is performed. At this time,
The operation of the line switching apparatus 50 is the same as that of the system 0 in FIG.

FIG. 8 shows that a loopback occurs in the node devices 13 and 15 due to the failure of the node device 14. Here, communication between the connected terminal device 32 and the partner terminal device 42 is impossible due to the failure of the node device 14, but communication lines for the other terminal devices are secured to enable communication.

The main operation of the line switching device is as described above.
All the selector circuits are controlled by one signal from the select signal generation circuit 51 to switch the communication circuit, and the communication path of the transmission data and the reception data of the terminal device is changed.

[0020]

As described above, according to the present invention, in the 1: 1 communication line superimposed on the 7: 7 communication line, the communication line capacity necessary for a certain set of 1: 1 communication is determined by the transmission capacity of the node device. If the transmission capacity does not exceed 1, there is an effect that 1: 1 communication can be performed for a plurality of sets with a transmission capacity of one set by performing line switching based on operation state information from each node device. Further, there is an effect that the remaining time slots can be effectively used, and functions such as loopback and bypass can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a block diagram of a line switching device in FIG. 1;

FIG. 3 is a block diagram of a node device in FIG. 1;

FIG. 4 is a system diagram when (a) 0 system and (b) 1 system of the 7: 7 communication line in FIG. 1 are used.

FIG. 5 is a system diagram of a 1: 1 communication line when the system 0 in FIG. 1 is used.

FIG. 6 is a system diagram of a 1: 1 communication line when the system 1 in FIG. 1 is used.

FIG. 7 is a system diagram of a 1: 1 communication line at the time of a transmission line failure in FIG. 1;

FIG. 8 is a system diagram of a 1: 1 communication line at the time of a node device failure in FIG. 1;

[Explanation of symbols]

 11-17 Node device 21-27 Terminal device 31-33 Terminal device 41-43 Terminal device 50 Line switching device 61-67 Transmission line 71-73 Signal line 81-83 Signal line

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-134647 (JP, A) JP-A-3-253145 (JP, A) Tomoshige Byoshi, five others, "Configuration of 150 Mbps optical loop type LAN" Proceedings of the IEICE Autumn Conference 1992, The Institute of Electronics, Information and Communication Engineers, September 15, 1992, B-427 (58) Fields studied (Int. Cl. ⁷ , DB name) H04L 12/28-12/46 JICST File (JOIS)

Claims (3)

(57) [Claims] 1. A first terminal device is connected to each node device of a bidirectional loop type LAN in which 2n + 1 (n is a positive integer) node devices are connected in a ring by two communication lines. And m-to-m (m ≦ 2n + 1) communication means for sequentially communicating between any pair of the first terminal devices using the first communication band of the loop-type LAN, and any of the node devices When one is the first, the second terminal device is connected to each of the even-numbered node devices, and at the same time, a common line switching device is connected to the odd-numbered node devices, and each of the adjacent node devices is connected. A third terminal device is connected to each switching output of the line switching device for selecting one of the two, and a second communication band multiplexed with the first communication band is used, and the second terminal device Between the corresponding third terminal device 1-to-1 communication at maximum n pairs of 1
A data transmission method comprising: one-to-one communication means. 2. The line switching device inputs the transmission line operation state information of the loop type LAN from each of the odd-numbered node devices, and receives a transmission data signal from the third terminal device and the second terminal device facing the transmission terminal. 2. The data transmission method according to claim 1, wherein the switching is performed by determining which of the adjacent odd-numbered node devices receives a signal from the device. 3. The loop-type LAN further multiplexes a third communication band with the first and second communication bands and uses a new one similar to the one-to-one communication means using the third communication band. 3. The data transmission system according to claim 1, further comprising one-to-one communication means.