JPS62104331A - Data transmission system - Google Patents

Abstract

PURPOSE:To obtain an economical system which facilitates channel control by setting low-speed data as the least significant bit in a frame used for the transmission of high-speed data and transmitting the high-speed data and low- speed data simultaneously when a request to send the low-speed data is made during the transmission of the high-speed data. CONSTITUTION:The output of a serial/parallel converting device except LSB information is inputted directly to a parallel/serial converting device 201. Low- speed data information of L bps is inputted to a transmission line 207 in addition to the LSB information and a select signal for selecting the LSB information and low-speed data information is also inputted to the transmission line 208. The low-speed data information is inserted into the sequence of the LSB information in the transmission frame of the high-speed data information with the select signal at intervals of K/(mL) bit, but when the select signal is low, the LSB information is selected and when high, the low-speed data information is selected. A received information sequence is inputted to the serial/parallel converting device 400 through a transmission line 403 and expanded into a parallel sequence of (m) bit and its signal speed becomes k/m bps.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a system for simultaneously transmitting digital high-speed data and low-speed data.

(Prior art) Conventionally, when communicating by simultaneously transmitting high-speed data and low-speed data using a digital line (for example, video and data in an image conference), the bandwidth for high-speed data transmission ranges from several 10M to several If 100 M bpa is required, transmission is performed by packet switching, or if high speed and real-time performance are required, an empty channel is secured and transmission is performed by line switching (details are available in 1982). "Computer Network" P published by Breakfast Shoten Yoshi
154 to P170). Similarly to high-speed data transmission, packet switching and circuit switching are used for low-speed data transmission, but the bandwidth is several 100 bpa ~
Since the transmission speed is several Mbps, packet switching is generally the most widely used method of transmission. In packet exchange, each packet is regarded as an independent unit of information, and the so-called datagram method is used to check the address of each packet and send it to the receiving side, and the other is the datagram method, which creates a logical communication path between the sender and receiver. There is a partial circuit method that does not refer to the address for each packet once the path is set. Although the datagram method does not require the setting of paths, it is inferior to the virtual circuit method in terms of transmission efficiency, so the virtual circuit method that sets logical paths is generally used. Conventionally, in order to transmit high-speed data and low-speed data simultaneously for communication,
Communication is performed by securing an empty channel for high-speed data, and by setting a logical path to transmit low-speed data using a packet-switched partial circuit method. Hereinafter, this logical path will be referred to as a low-speed data channel.

(Problems to be Solved by the Invention) In conventional systems, when communicating by simultaneously transmitting high-speed data and low-speed data, such as in image conferencing, a channel for high-speed data is secured, and a channel for low-speed data is It is necessary to set a logical path for In particular, when high-speed data communication is normally performed and a low-speed data transmission request occurs during the communication, and high-speed data and low-speed data are simultaneously transmitted, the conventional method is used when low-speed data transmission requests are infrequent. If both a high-speed data channel and a low-speed data channel are secured as in the above example, the usage rate of the low-speed data channel is low, resulting in poor efficiency and high cost. Another option is to set up a low-speed data channel each time a low-speed data transmission request occurs, and then release the channel each time the request decreases. Because of the steps involved in setting and opening the system, efficiency is reduced. In either method, it is necessary to manage both the high-speed data channel and the low-speed data channel, which complicates communication procedures.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for simultaneously transmitting high-speed data information and low-speed data using only high-speed data channels in communications that simultaneously transmit high-speed data and low-speed data, such as image conferencing using digital transmission. The purpose is to

(Means for Solving the Problems) The means provided by the present invention to solve the above-mentioned problems is a method of simultaneously transmitting digital high-speed data and low-speed data, in which the high-speed data channel is continuously transmitted. The high-speed data is transmitted using the high-speed data channel during a period when there is no request to transmit the low-speed data, and when there is a request to transmit the low-speed data during the transmission of the high-speed data. When this occurs, the low-speed data is placed in the least significant bit of the frame used for transmitting the high-speed data, and the high-speed data and low-speed data are transmitted simultaneously.

(Embodiment) FIGS. 1(a) and 1(b) show signal formats in an embodiment of the data transmission system of the present invention.

Bit 1 shown at 100 in the figure indicates the lowest bit (18B) in each frame. Currently, high-speed data information is transmitted at Kbps, and one frame is Mbit.
It consists of L bps, and low-speed data information is L bps.
It is assumed that the data is being transmitted by . In the following, a case will be described in which the low-speed data information is transmitted using the LSB of the high-speed data information frame.

Focusing on the LSB of each frame in Figure 1 (1k), the transmission rate is 2/m bp8, which is K/m bp8.
If ≧L, low-speed data transmission is possible, but if K/m×L, it is not possible, so K will be used in the following explanation.

It is assumed that K/m≧L holds between m, r, and +. Furthermore, the high-speed data information targeted by the present invention allows some transmission errors, as will be described later.

In this embodiment, in order to transmit low-speed data information of Lbpθ using LEB transmitted at K/m bps, data is transmitted every /(mL) frame as shown in FIG. 1 (1)). By inserting low-speed data information into frame 0LEIB, simultaneous transmission of high-speed data information and low-speed data information is performed. Conversely, on the receiving side, the low-speed data information sequence is received by sequentially outputting several LSBs for each /(mL) frame.

FIG. 2, FIG. 3, and FIG. 4 show an example of a specific device and signals for realizing the data transmission system of the above-described embodiment. Second
The figure is a block diagram of an example of a transmitting device, and FIGS.
II) is a signal diagram thereof, FIG. 4(a) is a block diagram of an example of a receiving device, and FIGS. 4(b), (C), and (d) are diagrams showing signals of the receiving device.

The transmitting device will be explained with reference to FIG. 2 and FIGS. 3(a) to (I). K bps high-speed data information 300 is input to the serial/parallel converter 200 via a transmission line 204, where it is expanded into an mbit parallel series. Figure 3 (
303 and 304 in b) are the serial/parallel converter 2, respectively.
It shows the output of 00 and 303 is the most significant bit of bitTn (
MSB), 304 is the lowest bit bit) (LSB)
) is shown. The m outputs of the serial/parallel converter are transmitted on transmission lines 205 and 206 at /mbpa, respectively. The I, 8B information of the high speed data information frame is obtained as one of the m outputs of the serial/parallel converter and is input to the selector 203 via the transmission line 206. Anything other than L8B information that is output from the serial/parallel converter is directly output.
It is input to the parallel/serial converter 201. In addition to the LSB information, L bps low-speed data information 308 is input to the selector 203 through the transmission line 207, and a selection signal 309 for selecting between the LSB information and the low-speed data information is also input through the transmission line 208. . According to this selection signal, the LB of the high-speed data information transmission frame shown in FIG.
Low-speed data information is inserted into the B information series every (mL) bit, but in the figure, when the selection signal 309 is LOW, L13B information is selected for K, and when it is HIGH, low-speed data information is selected. As a result, the output of the selector 203 is as shown in FIG.
．． They are inserted into the LSB information sequence in the order of 311, 312, etc. This output is sent to the transmission line 209 l)K
/mbps to the parallel/serial converter 201, and together with the output from the serial/parallel converter 200, it is converted into a Kbit information sequence as shown in FIG. I will be sent to Figure 4 (a
), the receiving side transmits the received information sequence 410 to the transmission path 40.
2 and 403, and the data on the transmission line 402 is directly sent to the receiving device as high-speed data information. On the other hand, the received information series 410 is input to the serial/parallel converter 400 through the transmission path 403, and is expanded into a parallel series of mbits, and the signal speed becomes 2/mbps. L out of m outputs
Only the SB information series 411 is input to the subsequent serial/parallel converter 401, where it is further converted to /(mL)b
It is expanded into a parallel series of it, and the signal rate is converted to L bps. The transmitted low-speed data information series 412 is obtained as one of the outputs of the serial/parallel converter 401 and is sent to the low-speed data information receiver via the transmission line 404.

As mentioned above, in the data transmission method of this embodiment, high-speed data information is transmitted at K bps using a frame composed of mbits, and when a request to transmit low-speed data occurs, the frame used for high-speed data transmission is L8BKL
Simultaneous transmission of high-speed data and low-speed data is possible by inserting low-speed data information of bps, but inserting low-speed data information as part of the high-speed data information in this way means that a type of transmission path error may occur. This can be said to be the same as deterioration of high-speed data information. In the data transmission system according to the present invention, a certain degree of transmission path error is allowed for high-speed data information, but the effect this has on the original high-speed data information will be explained.

Looking at each high-speed data frame, it is composed of mbits, so the weight of the information held by LI3B is 1/(2
-1) As mentioned above, in order to transmit low-speed data information of (Lbps), it is sufficient to insert the low-speed data information into the LSB of every (mL) frame, so its weight is (1/( 2-1>1*((mL)/K), and if the ratio of the transmission time of low-speed data to the time per unit time is small, the effect will be even greater, that is, the ratio of the low-speed data to the high-speed data The weight becomes even smaller.As described above, when LK is extremely large compared to L, that is, when K)L, or when the frequency of low-speed data transmission requests is small, low-speed data information is inserted in the 8B of the high-speed data information frame. The impact of this is small.

For example, if we consider a video as high-speed data, it is transmitted digitally at 100 Mbpg, but compared to that, low-speed data, such as 2400 bps, has an amount of information that is orders of magnitude smaller than that of high-speed data. There are many targets. In the above example, if the transmission frame of high-speed data information is made up of Bbits, the weight of low-speed data relative to high-speed data is 7*10-'
It's just a matter of degree. Moreover, it can be said that if the density of transmission times is low, the weight becomes even smaller.

(Effects of the Invention) According to the data transmission method of the present invention, when a low-speed data transmission request occurs during high-speed data transmission, when high-speed data and low-speed data are transmitted simultaneously, new low-speed data is Because it simultaneously transmits both data using only the already secured high-speed data channel without having to secure a dedicated high-speed data channel, it is more economical than conventional methods, and also eliminates the steps of setting up and opening low-speed data channels. This simplifies channel management.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are diagrams showing signals in an embodiment of the data transmission system of the present invention, FIG. 3(a) to (j) are diagrams showing signals in the transmitting device of FIG. 2, FIG. 4(a) is a block diagram showing a specific example of a receiving device that implements the embodiment, and FIG. (b) to (d) are diagrams showing signals in the receiving device. In the figure, 100 is the LSB of the high-speed data frame, 2
001 4001 401 is a serial/parallel converter, 20
3 is selector, 204,205°206.207,2
08,209,210.4021403 is the transmission line, 20
1 is a parallel/serial converter, 300 is a video frame, 30
1 is MSB, 302 is LSB, aoa* 304 is video information bit, 305e 306 = 307 is LB
Data information insertion position in B information series, 308 is data information, 309 is selection signal, 310.3119 312
is the data information inserted into the L8B information sequence, 313 is the transmission information sequence, 410 is the reception information sequence, 411 is the reception LS
The B series and 412 each indicate a received information series. Agent Patent Attorney Nobu Honjo Bento Box 1 (a) (b) Figure 2 Figure 3

Claims (1)

[Claims] In a method for simultaneously transmitting digital high-speed data and low-speed data, a channel for high-speed data is continuously secured, and during a period when there is no request to transmit the low-speed data, the high-speed data channel is used to transmit the high-speed data. If a request to send the low-speed data occurs during transmission of the high-speed data, the low-speed data is placed in the least significant bit of the frame used to transmit the high-speed data and the high-speed data and low-speed data are transmitted. A data transmission method characterized by simultaneously transmitting data.