拥塞控制算法的一种改进

The Improvement of Congestion Control Algorithm

由于无线网络具有较高的误码率,其数据包丢失概率较高,而TCP一旦发现数据包丢失会立即降低速率对其响应,网络吞吐量也会进一步降低,所以有必要对丢包原因做进一步分析,判断出是由于拥塞还是误码而导致的数据包丢失。TCP中的RTT(Round-Trip Time)可以较好地反映出当前网络的拥塞状态,为此,对TCP的拥塞控制算法改进,使用一种基于RTT拥塞判断方法对丢包原因做进一步识别,如果由于拥塞导致的丢包则降低速率,如果是误码等原因则不必降低速率,只需重传丢失的数据包,从而提高无线网络的吞吐量。

Because bit error rate of wireless networks and its packet loss ratio rate are very high,but TCP begins to lower data rate immediately to respond to it when it finds packets are lost, the thought would decline accordingly ,then it＇s necessary to make further analysis of the reason of packets loss ,to judge that the packet loss is because of congestion or bit error. RTT could better reflect the current congestion state of network,this paper would use a new method based on RTT to distinguish the packet loss to improve the congestion control algo-rithm,if the packet loss is because of congestion then the rate should be lowered,if it＇s because of bit error then it＇s not necessary to lower rate,only to retransmit the lost packet,which solves the data rate decline because of bit error, so the thought of wireless networks is enhanced.