Method for optimizing wireless video TCP transmission

Abstract

The invention relates to a method for optimizing wireless video TCP transmission, which comprising the steps of: collecting RTT information; receiving a report; setting a retransmission timer; processing the over time of the retransmission timer; and building an ACK report. Compared with the prior art, the method has a simple realization principle, and is effective to the most occasions with the wireless video TCP transmission. Furthermore, terminal node devices such as a video coder and a video display center, and the like are completely transparent, and the distribution of function modules are easy, so that the method can be used for a layer 2 switching device and a layer 3 route device.

Description

technical field [0001] The invention relates to a method for monitoring, modifying and injecting corresponding messages in a TCP connection by using an intermediate node in a TCP video service carried by a wireless network, in particular to a method for optimizing wireless video TCP transmission. Background technique [0002] An important factor for a TCP connection to obtain stable bandwidth is a stable RTT (transmission round-trip delay) value. If the RTT changes frequently, TCP cannot accurately estimate the delay time, so a short temporary delay increase may cause TCP to reduce the sending rate. Due to the error correction or retransmission mechanism of the link layer, the current wireless network shows that the packet loss rate on the air link is not high, and the three biggest problems in this type of network are: (1) sudden delay increase. Switching, low-level retransmission, and data blocking can all cause sudden increases in transmission delay. When it happens, t...

AI Technical Summary

Problems solved by technology

If the RTT changes frequently, TCP cannot accurately estimate the delay time, so a short temporary delay increase may cause TCP to reduce the sending rate

Due to the error correction or retransmission mechanism of the link layer, the current wireless network shows that the packet loss rate on the air link is not high, and the three biggest problems in this type of network are: (1) sudden delay increase

Then the sender immediately receives the ACK, and the sender cannot tell which is the retransmitted ACK, which triggers the sender's "slow start" process, which causes a burst of data transmission during the slow start process, and then causes congestion control

(2) RTT and bandwidth change frequently

The characteristics of wired links and wireless links are different, and the optimization for TCP protocol is difficult to apply to both wired and wireless links

In the application of high-bandwidth wireless video surveillance, high requirements are placed on the stability of wireless bandwidth, and the decline in the actual transmission bandwidth of TCP connections will inevitably affect the effect of video surveillance

If the transmission bandwidth drops greatly, the receiver of the video will experience image jitter, hysteresis, or even mosaic.

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