Delay control method of open loop narrow-band channel

Abstract

The invention discloses a delay control method of an open loop narrow-band channel. Transmission delay is reduced by increasing the interface rate; the delay is estimated by using a data packet as a unit so that data packet delay can be known just at a sending end and DTE (Data Terminal Equipment) is kept no buffer area accumulation; the length of the buffer area in the DCE (Data Communications Equipment) is estimated in real time to effectively avoid the disorder of the data packet, caused by the random discarding of the data due to overflow of the buffer area in the DCE; a transmission priority is set for each data packet to ensure that the data with highest priority are sent firstly. The invention further provides a realization method of recursion, which has the advantages of low cost and good instantaneity and can be applied to short waves, ultra-short waves, dialing networks, special lines and other low-speed communication transmission systems.

Description

technical field [0001] The invention relates to a delay control method of an open-loop narrowband communication channel. Background technique [0002] Data communication is generally composed of data terminal (DTE), data circuit terminal equipment (DCE), channel and other parts. There are many interface modes between DTE and DCE, such as figure 1 An example of RS232 serial port between DTE and DCE is given. [0003] Suppose the channel rate is S1, the interface rate between DTE and DCE is S2, and the source rate is S3. In narrowband channels, due to the limited channel rate, in order to avoid problems such as buffering, loss, and data confusion, S1 and S2 are required to be equal in most cases. Next, in order to better analyze the delay, the end-to-end transmission delay will be modeled, such as figure 2 shown. [0004] In most cases, the transmission of information appears in the form of data packets, which is reflected as a byte stream of a certain length from the ph...

AI Technical Summary

Problems solved by technology

As shown in Table 1, in the case of numbers 1, 2, 3, and 4, a buffer overflow will occur, and once it occurs, the data will be discarded randomly, thus destroying the structure of the data link layer, resulting in The correct message cannot be received correctly

[0016] In the existing processing methods, S1 and S2 are required to be equal in most cases. This method will lead to an increase in delay, and it is unavoidable that when S3>S2, the accumulation of buffers in DTE will cause delay increase and data loss. The problem of missing at random

At the same time, because the narrowband channel bandwidth is extremely limited, the priority transmission of important data must be guaranteed, which is also a key issue in narrowband channel data transmission

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