JPH0630510B2 - Data transmission equipment - Google Patents

Description

Description: 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 suitable for an information transmission system or the like that requires high-speed and large-capacity data transmission.

[Prior art]

As an example of an information transmission system, a system is known in which necessary data is transferred between information devices such as a plurality of computers, data file devices, or display devices. Such an information transmission system is configured by connecting each information device to, for example, one signal transmission line in a loop shape, and generally providing a signal transmission processing device called a node station at the connection point. There is. The node station (hereinafter, abbreviated as NST) performs transmission / reception processing of data to be transferred, and has a function of determining transfer data destined to an information device connected to the NST and fetching the transfer data from a transmission line. When an information device connected to the NST gives a command to transfer data to another information device, the exclusive state of the transmission line (vacant time, etc.) is judged and the data is sent to the transmission line. It is equipped with data transmission control functions such as functions. Further, in the transmission path between NSTs, data is converted into a serial signal and transferred. When the data transferred between the information device and the NST is a parallel signal, the parallel signal is converted into a serial signal. It has a conversion function.

According to the data transmission / reception processing method in the conventional NST,
Only one type of data can be transferred between NSTs at the same time, and if the transmission path is exclusively used, data cannot be transferred simultaneously between other information devices. Also, the data transfer speed of the conventional one is
The speed was limited mainly due to the physical signal transmission characteristics of the transmission line, and the maximum speed was several Mbit / sec to several tens Mbit / sec.

On the other hand, the data processing speed of information devices has been remarkably increased, and ultra-high-speed processing of, for example, several hundreds Mbit / sec to Gbit / sec has been demanded. Further, there has been a demand for a large capacity even with respect to the amount of transferred data.

However, when the data transfer rate in the information transmission system is medium to low as described above, the coordination of the processing speeds cannot be taken, and the ultra-high speed of the information device may be meaningless. Therefore, there is a demand for an ultra-high data transfer rate and a large capacity.

[Object of the Invention]

An object of the present invention is to provide a data transmission device capable of simultaneously transmitting information to a plurality of distributed information devices by one transmission and increasing the data transmission per unit time.

[Outline of Invention]

A feature of the present invention is a data transmission device as set forth in the claims, and in particular, the multi-channel switching means is provided with an input channel from the channel dividing means as an output channel portion to the channel multiplexing means. At the same time as connecting, it has a function of connecting to the output channel part of the data to the information device, so that while fetching a certain data to a specific information device, it can also be connected to an information device connected to another data transmission device at the same time. That is, it is possible to import the same data.

Example of Invention

 Hereinafter, the present invention will be described based on examples.

FIG. 1 is a block diagram of an information transmission system of an embodiment to which the present invention is applied. In the figure, a computer 1 or information devices such as a file 5 and a CRT 6 are connected to a loop-shaped common transmission line 2 via an NST 3.

The signal transmitted through the common transmission line 2 is, for example, a transmission frame having the configuration shown in FIG. The transmission frame shown in FIG. 2 has a length of 125 bits and 250 ns, which is the same length as a conventional single 8-bit serial signal. The 125 bits are time-divided into a 5-bit frame synchronization pulse F and eight sub-frames SF1 to SF8, and each sub-frame is time-divided into transmission channels CH1 to CH15 consisting of one bit unit. A transmission frame is formed in this way, data transmitted and received between the computer 1 and the file 5 is converted into an 8-bit serial signal, and each bit signal is assigned to the same channel of the subframes SF1 to SF8. The transmission channels are the general channel (CH1) 7 and the individual channels (CH2 to CH1).
5) It is divided into 8. The overall channel 7 is for medium or low speed data transmission between the computers 1 or the like 2
It is used as a transmission channel for transmitting line control management information such as connection or release of the individual channel 8 used for data transfer between two NSTs. The connection or disconnection of the individual channels 8 is controlled by the node station 3.

Next, the node station 3 will be described with reference to the block diagrams shown in FIGS. All signals in the transmission system of this embodiment are optical signals. As shown in FIG. 3, the node station 3 includes an optical switch 3-.
1, transmitter 3-2, multiplexer 3-4, receiver 3-3,
Multiplexing / separating device 3-5, multi-channel switching switch 3-
6, line control management device 3-7, individual channel interface 3-8, and general channel interface 3
-9 and formed. The frame signal transmitted from the transmitter 2 is received by the receiver 3-through the optical switch 3-1a.
The frame signal received by the node 3 and transmitted from the node station 3 on the contrary is transmitted from the transmitter 3-2 to the optical switch 3-.
It is adapted to be sent to the transmission line 2 via 1b. The optical switch 3-1 has a circuit for bypassing the node station 3 without taking in a frame signal from the transmission line 2 when the node station 3 is abnormal.
The frame signal received by the receiver 3-3 is
Each transmission channel CH1 in the demultiplexer 3-5
~ Is separated into serial signals for each CH15. That is, the receiver 3-3 and the multiplexer / demultiplexer 3-5 are constructed as shown in FIG.
The frame signal from 1a is an ultra high speed demodulation element 3-3a, A
After being processed through the GC amplifier 3-3b, the equalization filter 3-3c, the identification reproduction 3-3d, and the code conversion 3-3e, it is transferred to the demultiplexing circuit 3-5a. The identification reproduction 3-3d and the demultiplexing circuit 3-5a are
The timing of signal processing is controlled according to the timing signal extracted by the timing extraction 3-3f. The signals separated by the demultiplexing circuit 3-5a for each of the channels CH1 to CH15 are sent out through the optical interface 3-5b.

The data of the generalized channel 7 thus separated is sent to the line control management device 3-7, while the contents of the individual channel 8 are transferred to the multi-channel switching switch 3-through the line provided corresponding to each channel. 6 is sent. Note that FIG. 3 shows the case of three individual channels 8 for the sake of simplicity.

The line control management device 3-7 receives the received general channel 7
If the contents of the above are received data to the computer 1, the data is transferred to the computer 1 via the general channel interface 3-9. When the content of the data transferred to the computer 1 is individual channel switching, a channel switching command 3-10 is output to the multi-channel switching switch 3-6 via the line control management device 3-7. There is. This multi-channel switching switch 3-6 is an individual channel CH1 to CH15 of the receiving side transmission line and the transmitting side transmission line.
Has a function of switching connection or disconnection according to the switching command 3-10, and is formed by including space division switches 3-6a to 3-6b as shown in FIG.

FIG. 5 schematically shows a switching state of the individual channels at a certain time. According to this example, the contents of the channel CH1 are destined for the file 5 which is the information device connected to the NST3, and the data of the channel CH1 transferred from the demultiplexing device 3-5 is transferred to the individual channel. The paths of the space switches 3-6a and 3-6c are switched as shown in the figure in order to transfer to the file 5 which is an information device via the interface 3-8. The data of the channel CH2 is destined to another NST3, and is not taken into the information device connected to the NST3 but bypassed and multiplexed by the multiplexer 3.
The paths of the space switches 3-6a and 3-6b are switched so as to be sent out again to the transmission path 2 via -4. On the other hand, the data of the channel CH3 is addressed to the NST3 and other NST3 (for example, broadcast data), and is taken into the information device connected to the NST3 and at the same time bypassed to the multiplexer 3-4. The space switches 3-6a and 3-6b to be transmitted again to the transmission path 2 via
And 3-6c are switched. Further, when there is data to be transmitted from the file 5 connected to the NST 3 to another information device, the data transmitted from the individual channel interface 3-8 is sent to the empty channel CH1 so as to send the space division switch. The route 3-6d is switched. As described above, the multi-channel switching switch 3-6 connects the receiving side and the transmitting side individual channels 8 for the data bypassing the NST 3 based on the channel switching command, and the receiving side for the fetched data. The individual channels are connected to the individual channels 3-8, and the data to be transmitted is controlled so as to be sent to a designated empty channel.

The transmission data output from the transmission end of the multi-channel switching switch 3-6 is converted into the above-mentioned frame signal by the multiplexing device 3-4, and the optical switch 3 is transmitted from the transmitter 3-2.
-1b is sent to the transmission line 2. That is, the multiplexer 3-4 and the transmitter 3-2 are the sixth
The configuration is as shown in the figure, and each channel CH1 connected to the transmission end of the multi-channel switching switch 3-6.
-CH15 are connected to the multiplexing circuit 3-4b via the optical interface 3-4a. This multiplexing circuit 3-
The frame signal 3-4c multiplexed by 4b is transferred to the code conversion circuit 3-2a together with the clock signal 3-4d. The frame signal transferred to the code conversion circuit 3-2a is a laser modulation stabilization circuit 3-2b,
Optical switch 3 via ultra high speed modulation semiconductor laser 3-2c
-1b is being transferred. The ultra-high speed modulation semiconductor laser 3-2c is monitored by a laser monitor (not shown).

As described above, in each NST3, the individual channels 8 are connected or released based on the data transmitted by the general channel, and a plurality of direct transmission paths including the individual channels 8 are provided between the predetermined NST3. They are formed so that data can be transmitted at the same time.

Here, the data transmission of the frozen channel is shown in FIG.
This will be described with reference to FIG. In the general channel 7, data is transferred by a well-known packet exchange method, and each NS
The T3s are free to communicate with each other. Since the control channel 7 transmits the data for connection and release control of the individual channel 8 as described above, it is possible to set the N
In response to the data transfer request in ST3, it is necessary to control the dynamics so as to occupy the transmission channel.

Figure 7 is called the Token method,
This is an example of transmitting data from NST · NO.2 to NST · NO.1. The figure shows NST NO.1 in charge of channel 7
Shows the time change of the data flowing on the loop, and the symbol R represents the receiving side of the NST, and T represents the transmitting side. As shown in the figure, a free token (FT) FT that occupies the general channel 7 and permits transmission of a packet PKT constantly circulates in a loop, and has a packet PKT to be transmitted.
2 rewrites this into a reserve token RT and subsequently sends out a packet PKT. When the transmission of the packet PKT is completed, the NST · NO.2 transmits the free token FT to allow another NST to occupy the general channel 7.

FIG. 8 shows what is called a time slot system, which is a time slot TS of a fixed length on the loop.
The packet PKT is transmitted by occupying one or a plurality of packets. FIG. 8 shows three examples of the time slot TS. Although not shown, the header portion of the time slot TS is provided with a display signal indicating whether the time slot TS is in use or free. , Occupancy control is performed.

The data in the packet PTK transmitted via the general channel by any one of the above methods contains the line control management information. As described above, this line control management information is assigned to the individual channels CH1 to CH15 that have been allocated.
It is composed of information necessary for forming a communication path, such as the number of. For example, when there is no individual channel to be allocated, the line control management is performed to notify the NST of the transmission request source to that effect, open the transmission path established halfway, and try again to establish the transmission path after a certain period of time. It consists of information. As shown in FIG. 9, when the data is transmitted from the NST3TX to the NST3RX, the control channel information is transmitted by the general channel 7 to the NS.
Sent from T3TX. Based on this NST3RE
And NST3RX responded, NST3TX and NST3RX
The required number of individual channel 8 transmission paths are formed between and. After these individual channels 8 are formed, their N
The individual channel 8 is occupied until the data transmission during ST3 is completed. Similarly, a dedicated transmission channel corresponding to the number of individual channels is formed between the other NSTs 3 and data is transmitted and received between a plurality of information devices at the same time. The conceptual configuration of the transmission channel formed at a certain point in time is schematically shown in FIG. As shown in FIG. 10, the general channel 7 is established via all NSTs 3 connected to the common transmission line 2, and medium-low speed data transmission between computers 1 or individual NST 3s. The line control management information for establishing the channel 8 is transmitted. Further, as shown in the figure, the individual channels 8 are shown to be individually established between the desired computer 1 and the file 5 or between the desired computer 1 and the CRT 6.

In the above embodiment, the integrated channel 7 is incorporated in the same frame signal as the individual channel 8, but a loop-shaped transmission line may be separately provided for the integrated channel.

〔The invention's effect〕

As described above, according to the present invention, it is possible to form a plurality of individual transmission channels in a single medium / low speed transmission line, and thereby to transfer data between a plurality of information devices at the same time. In addition to the above, there is an effect that the data transfer amount per unit time can be significantly increased.

Further, these effects have the effect of facilitating the realization of a multiple information transmission system required to transmit various types of information at the same time and at high speed, and further improving the system performance and efficiency. .

Further, according to the present invention, when the image information is assigned to a certain channel, it is possible to simultaneously transmit (broadcast) to n dispersed image display devices by using only one channel.
There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an information transmission system of an embodiment to which the present invention is applied, FIG. 2 is a configuration diagram of a transmission frame signal of the embodiment, and FIGS. 3 to 6 are diagrams of a node station of the embodiment. Block diagram, FIGS. 7 and 8 are diagrams for explaining the data transmission method of the general channel, FIG. 9 is a diagram for explaining the route establishment of the individual channel, and FIG. 10 is for the entire information transmission system. It is the figure which showed typically the established transmission channel. 1 ... Computer, 2 ... Transmission path, 3 ... Node station, 5 ... File, 6 ... CRT, 7 ... General channel, 8 ... Individual channel, 3-1 ... Optical switch,
3-2 ... Transmitter, 3-3 ... Receiver, 3-4 ... Multiplexing device, 3-5 ... Multiplexing / separating device, 3-6 ... Multi-channel switching switch, 3-7 ... Line control management device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Yasumoto 5-2-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi Omika Plant, Ltd. (72) Inventor Matsuaki Terada Aso-ku, Kawasaki-shi, Kanagawa 1099, Ozenji, Ltd., Hitachi, Ltd. System Development Laboratory (72) Inventor, Masahiro Takahashi 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi Ltd., Hitachi, Ltd. (72) Inventor, Mitsuo Yamada Chiyoda-ku, Tokyo Kanda Surugadadai 4-chome Hitachi Co., Ltd. Panel of referee Judge Masanori Hirano Judge Gouki Nakamura Judge Mitsutake Fujiuchi (56) Reference JP 54-78907 (JP, A) JP 58-40947 (JP, A)

Claims (1)

[Claims] 1. A data transmission apparatus, wherein a plurality of data transmission apparatuses are connected by a loop-shaped transmission line, and information apparatuses connected to each data transmission apparatus transmit and receive data using arbitrarily divided channels. In each data transmission device, a channel division means for physically separating the multiplexed channel group on the transmission line into individual channels in a part to be received from the transmission line, and a part for individually transmitting to a part to be transmitted to the transmission line. Channel multiplexing means for multiplexing and outputting the selected channels on the transmission path, an input channel part from the channel dividing means, an output channel part to the channel multiplexing means, and an information device connected to the data transmission device. And a multi-channel switching unit having a data output channel section of the information device and a data input channel section of the information device. The channel switching means has a function of connecting a certain input channel from the channel dividing means to an output channel portion to the channel multiplexing means and at the same time connecting to an output channel portion of data to the information device. Data transmission equipment.