综合无线错误丢包以及拥塞丢包事件的统计特征,基于丢包区分,本文提出一种适用于流媒体传输的无线TCP友好速率控制(Wireless TCP—Friendly Rate Control,WTFRC)方程并建立实用的速率控制机制.该机制包括服务器或者代理发送端和用户接收端两部分,分别负责往返传输时间(Round-Trip Time,RTT)估计、发送速率估计调整和丢包区分、丢包率(Packet Loss Ratio,PLR)统计、接收速率估计.仿真结果验证了该机制能够获得较高的吞吐量和较平缓的发送速率,并具备较好的TCP友好特征.
Considering statistic features of packet loss due to wireless error and congestion events ,this paper proposes a wireless TCP-friendly rate control (WTFRC) equation for streaming media delivery based on loss differentiation. Besides, a practical rate control mechanism is constructed. Our architecture includes sender functionality on content server or proxy side and receiver functionality on client side. The former is in charge of loss events differentiation, packet loss ratio (PLR) and receiving rate estimation. The latter is in charge of round-trip time (RTT) estimation, sending rate evaluation and adjustment. Simulation results demonstrate that higher throughput, better fairness and smoother sending rate can be achieved by our proposed mechanism.