一种适用于地球空间传感器网络的TCP Vegas模型

针对地球空间传感器网络中由正反向链路带宽不对称引起的正向链路吞吐量下降问题，提出一种基于时延且能够维持反向链路确认频率的拥塞控制模型。该模型基于反向链路中确认分组的排队时延，在反向链路发生拥塞时，降低确认分组的发送频率，以缓解反向链路的拥塞程度；而在反向链路没有发生拥塞时，加快确认分组的发送频率，以提高正向链路中数据分组的吞吐量。同时，该模型将确认分组的延迟发送时间追加到最小往返时延中，提高了最小往返时延的准确程度，从而提升模型的正向链路拥塞控制效果。仿真试验结果表明，该模型可以有效地解决由于反向链路拥塞所造成的正向链路吞吐量低的问题。

A TCP Vegas Model for Geospatial Sensor Networks

To solve the problem that the throughput degradation in the forward link led by the bandwidth asymmetry of the geospatial sensor networks, this paper proposes a congestion control model which can maintain the reverse link acknowledgement frequency based on delay time. The model, which is based on the queuing delay of the packet in the reverse link, can reduce the sending frequency of the acknowledgment packet to alleviate the congestion of the reverse link, when congestion occurs on the reverse link; and can increase the sending frequency of the acknowledgment packet to improve the throughput of the forward link data packets, when no congestion occurs on the reverse link. Furthermore, the model, which adds the delay time between two continuous acknowledgment packets to the base round-trip time, can make the base round-trip time more accurately, thereby improving the congestion control effect of the model on the forward link. The results of the simulation indicate the problem of the low throughput in the forward direction caused by the congestion in the reverse direction can be solved.