适用于卫星网络的TCP跨层改进机制

该文提出基于跨层信息交互，将链路层ARQ重传状态信息通知TCP的机制，避免了链路层重传引起的时延变化对TCP的不利影响。该机制使用完全可靠选择性重传ARQ为TCP提供可靠的链路，避免卫星链路上发生丢包，并且不必要求链路层保证包按序递交，消除了重排序的等待时延，适合带宽时延积较大的卫星网络。仿真结果表明，能显著提高TCP在卫星网中的性能，特别是在误帧率较高条件下。

A Cross-layer Mechanism to Improve TCP Performance in Satellite Networks

A mechanism is proposed to notify the link layer ARQ retransmission state information to TCP by the cross-layer information exchange. It can avoid the negative effect of delay variation on TCP due to the link layer ARQ retransmission. The perfectly-persistent selective repeat ARQ is adopted to offer a reliable link to TCP to avoid packet loss in satellite links. It does not require the in order delivery at the link layer, then the delay of waiting for reorder is eliminated. The mechanism is fit for satellite networks with big bandwidth delay product. Simulation results validate that it can greatly improve TCP performance in satellite networks, especially when the error frame rate is high.