基于NS仿真的无线自组网TCP性能研究

Research on TCP Performance Based on NS Simulation in Ad Hoc Network

由于Ad Hoc网络具有多跳、无线连接的特点,其TCP性能成为Ad Hoc网络研究的重点.考虑Ad Hoc网络的多跳拓扑及无线分组丢失,根据TCP主流版本的拥塞控制规则,基于NS实验分析了TCP窗口及吞吐量性能.研究表明:基于有线网络设计与优化的TCP版本,并不都适合于Ad Hoc网络.Tahoe不但将TCP窗口维持在一个较高的数值上,而且在主流TCP版本中吞吐量性能也是较好的.另外,实验与分析也显示,除了无线分组丢失,超时成为影响Ad Hoc网络TCP性能的重要因素.

Ad Hoc network has the characteristics of multi-hop and wireless channel, so TCP performance has become the emphasis of Ad Hoc network research. Taking multi-hop and wireless packet loss in Ad Hoc network into account, and on the basis of general TCP version congestion control principle and NS experiments, TCP window size is analyzed. The study reveals that not all TCP versions are suitable for Ad Hoc network. TCP-Tahoe can maintain higher level of TCP window and the network throughout of TCP version is better. Moreover, experiment and analysis indicate that time-out is also an important factor affecting TCP performance besides wireless loss in Ad Hoc network.