JPS62190954A - Multiplexing method for burst with priority - Google Patents

Abstract

PURPOSE:To obtain both the same high transmission efficiency with a queueing method and the same short delay time with a discarding method by adding a control bit sequence for transmitting information with high priority and a control bit sequence indicating the end of the transmission of the information with high priority to a head and a tail respectively and transmitting the information with high priority. CONSTITUTION:An information input detecting circuit 13 informs a multiplexing control circuit 14 of the input of burst information and also detects the priority of the input information to informs the multiplexing control circuit 14 of it. The multiplexing control circuit 14 commands a control bit sequence generating circuit 18 to output the control bit sequence indicating the transmission of the information with high priority at the start of the transmission of each piece of burst information and also commands a control bit sequence generating circuit 19 to output the control bit sequence indicating the end of the transmission of the information with high priority at the end of the transmission. This method is almost equal in transmission efficiency to and shorter in delay time than the queueing method. Further, its delay time is almost equal to that of the discarding method and the transmission efficiency is higher.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a burst multiplexing method in which information having different priorities is assembled into burst frames and multiplexed and transmitted.

(Prior art and its problems) Conventionally, in the burst multiplexing method in which information is assembled into burst frames and multiplexed and transmitted, the burst frame length is relatively short, and in packet transmission, which is a type of burst multiplexing method,
In CCITT As a method of Waiting method ■ (Waiting method) As an example, the contents of the multiplexed frame in response to the input of al are shown in Figure 1 (bl), and the priority of the information that is already being transmitted is changed to the information that is newly requested to be transmitted. If the priority is lower than the priority of An example of this is shown in Figure 1 (Figure 1 (C) shows the contents of the multiplexed frame for the input of al). Here, A is the burst information A, and B is the burst information JIB, B', B'. is part of burst information B, and B
=B'+B''. In addition, ■ is a control bit string indicating that information with a higher priority is to be transmitted, and E is a control bit string indicating that transmission of information with a higher priority is to be terminated.

However, these methods are suitable when the data length is relatively short, and when the data length is increased, they have the following drawbacks.

In method (2), the waiting time until the start of transmission of high-priority information increases, so the transmission delay time increases, and it becomes impossible to comply with the permissible transmission delay time.

In method (2), the amount of invalid information increases, resulting in poor transmission efficiency.

(Objective of the Invention) An object of the present invention is to provide a new prioritized burst multiplexing method that combines high transmission efficiency equivalent to the waiting method and low delay time equivalent to the discarding method in multiplex transmission of burst frames with different priorities. The objective is to provide a method for

(Structure of the invention) (4-1) Differences between the characteristics of the invention and the conventional technology The present invention has the following features:
If the priority of information that is already being transmitted is lower than the priority of newly generated information, the demultiplexer (
A control bit string (■ sequence) for indicating the transmission of high-priority information (DMUX) and a control bit string (E sequence) for indicating the end of transmission of high-priority information are added to the beginning and end, respectively. The main feature is that the transmission is performed, and then the untransmitted portion of the information whose transmission was previously stopped is transmitted.

The conventional technology is to transmit high-priority information.
The difference is that priority transmission is performed using a control bit string for indicating to the MUX and a control bit string for indicating the end of transmission of high priority information.

(f As an example when there are two precedence levels, see Figure 1fd
) shows the arrangement of frames after multiplexing for the input of burst information of al. Fig. 2 shows an example where there are three priority levels. is in the order of A, B, C. Also, C''.

c", c" is part of C, c = c' + c'
″+C゛.

(4-2) Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a configuration example of a priority burst multiplexer (MUX) for performing such transmission, and FIG. 5 shows a configuration example of a demultiplexer. In FIG. 3, burst information to be transmitted is input to an information input terminal 11. The information input interface circuit 12 is electrically terminated, and configures information that does not have a predetermined frame structure into a fixed frame 1-frame, and the information input detection circuit 13
to be transmitted. The information input detection circuit 13 notifies the multiplexing control circuit 14 of the input of burst information, detects the priority of the input information, and notifies the multiplexing control circuit 14 of the priority. The multiplexing control circuit 14 instructs the information writing control circuit 15 to start writing, and the information writing control circuit 15 writes input information to the burst information storage circuit 16 based on the instruction. If the priority of the information being read at this time (referred to as burst information N) is lower than the notified priority, the multiplexing control circuit 14 performs the following processes (1), (2)
), perform (3).

(1) By instructing the information read control circuit 17 to stop reading burst information, the burst information storage circuit 1
6. Temporarily stop reading the information.

(2) instructing the control bit string generation circuit 18 to output a control bit string indicating output of higher priority information;
Control bit string generation circuit 18 outputs a control bit string to information output interface 19 according to this instruction.

(3) By instructing the information read control circuit 17 to output higher priority information, the information read control circuit 17 sells 8 pieces of high priority information from the burst information storage circuit 16 to the information output interface 19. .

If there is an input notification of higher priority information while reading this burst information, the multiplexing control circuit 14 performs the processes (1) to (3). If the priority of the notified input information is not higher than the priority of the information being transmitted, the information is added to the queue. If there is no manual notification of high priority information and all of this information (burst information N) has been read out, a control bit string is output to the control bit string generation circuit 18 indicating that transmission of the high priority information is to be terminated. Instruct. If there is untransmitted information of burst information N and the information being transmitted is equal to or higher than the priority level of information N, the multiplexing control circuit 14 indicates that information with a higher priority is to be transmitted at the start of transmission of each burst information. The control bit string generation circuit 18 is instructed to output a control bit string, and at the end of transmission, the control bit string generation circuit 18 is instructed to output a control bit string indicating that transmission of high priority information is to be terminated.

The information read from the burst information storage circuit 16 and the control bit string output from the control bit string generation circuit 18 are output from the multiplexed information output terminal 20 to the multiplexed transmission line via the multiplexed information output interface circuit 19. .

An example of the above multiplexing algorithm in the multiplexer is shown in FIG.

According to the present invention, the information multiplexed as described above can be separated by the demultiplexer shown in FIG. In FIG. 5, burst information transmitted through a multiplexed transmission path is transmitted to a demultiplexer. The burst information input to the multiplexed information input terminal 51 is transmitted to the control bit detection circuit 53 via the multiplexed information input interface circuit 52. The control bit detection circuit 53 detects the ■ sequence and the E sequence from the transmitted information bit string, and notifies the demultiplexing control circuit 54 of the detected sequences. Demultiplexing control circuit 54
When receiving the detection notification of the I sequence, it notifies the information write control circuit 55 of the write start position, and the information write control circuit 55, based on this position information, writes the information after the ■ sequence to the burst information storage circuit 56. Write. Further, upon receiving the detection notification of the E sequence, the demultiplexing control circuit 54 notifies the information readout control circuit 57 of the readout start position, and the information readout control circuit 57 uses the burst information storage circuit based on this positional information. The output route setting circuit 5 outputs the burst information transmitted immediately before the E sequence in 56.
Output to 8. The output route setting circuit 58 sets the output route based on address bits in the header portion of the burst frame.

An example of the demultiplexing algorithm of the above demultiplexing device is shown in FIG.

In addition, an example of the structure of a burst information frame is shown in FIGS. 7(a) and 7(b).
). Here, the F sequence is a control bit string that indicates the beginning and end of a frame.

In particular, (b) shows the case where a control bit string is added for preferential transmission. Furthermore, in order to make the I sequence and E sequence irrelevant to the information to be transmitted, the HDLC
(Formerly gh-1evel Data Link Cont
rol) procedures to maintain code independence. Table 1 shows examples of combinations of each sequence and bit string. In the case of Table 1, if there are four consecutive bits of value 1, a bit of value O is inserted to maintain code independence.

Table 1 Qualitative comparison of the transmission delay time and overall transmission efficiency of high-priority information in the multiplexer between the conventional method and the method of the present invention in a multiplexing method with such priorities (
The results of 2-level priority are shown in Figure 8 ia) (b)
Shown below. Here, (transmission efficiency) = (bit amount of burst frame output by MIX) Also, in each case of (a) and (b), the priority level is 2.
The average data length and occurrence probability of high-priority information are constant, and the average amount of generated information per unit time of low-priority information is constant. One line is provided between the MUX and DMUX, and this is an example where the usage rate of the line is medium. Further, the transmission efficiency is the ratio of bits a of valid burst information arriving at the DMUX to the bit amount of the burst frame outputted by the MUX.

To: waiting time T due to collision between high priority information,: delay time ε due to transmission of I sequence. 2 Decrease in transmission efficiency due to bits other than burst information in frames such as F sequence and header ε1: - Decrease in transmission efficiency due to extra transmission of sequences and E sequences As is clear from Figure 8, the waiting method As the average data length of burst information with low priority increases, the transmission efficiency does not change, but the average transmission delay time in the multiplexing device for burst information with high priority increases. In the discard method, the transmission delay time is very small, but the low priority information that was being transmitted when the high priority burst information occurs becomes invalid, so the transmission efficiency is lower than the waiting method, and the average data length is The transmission efficiency gradually deteriorates as the time increases.

Compared to the waiting method, the method of the present invention has almost the same transmission efficiency and shorter delay time. Furthermore, compared to the discard method, the delay time is almost the same, and the transmission efficiency is high.

As is clear from this result, the present invention has higher transmission efficiency and can significantly reduce delay time than the conventional method.

(Effects of the Invention) As explained above, when high-priority burst information is transmitted by the method of the present invention, neither delay time nor transmission efficiency depends on the data length of low-priority information. When the information data length is long, this method has the advantage of being able to perform transmission with higher transmission efficiency and shorter delay time than conventional waiting methods and discarding methods.

[Brief explanation of drawings]

FIG. 1 is a signal sequence diagram showing an example of a prioritized burst multiplexing method when there are two priority levels, and FIG. 2 is an example of the multiplexing method of the present invention when there are three priority levels. FIG. 3 is a block diagram showing a configuration example of a priority multiplexing device according to the present invention, FIG. 4 is a flowchart showing a multiplexing algorithm of the multiplexing device, and FIG. FIG. 6 is a flowchart showing a demultiplexing algorithm of the demultiplexing device, FIG. 7 is a side view of the structure of a burst information frame, and FIG. is a characteristic diagram qualitatively comparing the transmission efficiency and delay time characteristics of the system of the present invention and the conventional system. 11... Information input terminal, 12... Information input interface circuit, 13... Information human power detection circuit, 14
...Multiplexing control circuit, 15... Information writing control circuit, 16... Burst information storage circuit, 17...
Information reading control circuit, 18... Control bit string generation circuit, 19... Multiplexed information output interface circuit, 20... Multiplexed information output terminal, 51... Multiplexed information input terminal, 52... multiplexed information input interface circuit, 53... control bit string detection circuit,
54... Demultiplexing control circuit, 55... Information writing control circuit, 56... Burst information storage circuit, 57
... Information readout control circuit, 58 ... Output route setting circuit, 59 ... Information output interface circuit,
60... Information output terminal.

Claims (1)

[Claims] In a prioritized burst multiplexing method in which information is assembled into burst frames, queued, and transmitted with priority, burst information having a higher priority than burst information that is already being transmitted is given priority. In order to transmit
Transmission of the burst information frame being transmitted is temporarily stopped, a control bit string indicating that high-priority information is to be transmitted is added to the beginning of the high-priority information, and transmission of the high-priority information is ended at the end. A prioritized burst multiplexing method characterized by transmitting a burst information frame to which a control bit string indicating that a burst information frame is to be transmitted is transmitted, and then transmitting the untransmitted portion of the burst information frame whose transmission was once stopped. .