影响最佳UDP分组长度的主要因素的研究

为给无线Ad Hoc网络设计者提供参考依据，本文基于场景，用仿真方法研究了网络传输CBR业务时影响最佳UDP分组长度的主要因素。仿真中分别采用了AODV和DSR路由协议，并考虑了信道无误码及有误码两种情况。结果表明，路由协议、业务强度、信道误码率都是影响最佳UDP分组长度的重要因素。在无差错信道条件下，AODV协议对应的最佳UDP分组长度比DSR协议的要短一些；随着业务强度的增强，最佳UDP分组长度变长。信道误码率BER为10^-4 时的最佳UDP分组长度比无差错信道条件下的短。当采用的分组长度由最佳长度逐渐增加时，网络性能迅速变差。

Study on Main Factors Affecting the Optimal UDP Packet's Length

To provide reference for mobile Ad Hoc network designers,the main factors which affect the optimal UDP(User Datagram Protocol) packet's length when transmitting CBR traffic is studied by simulation in this paper.Both AODV and DSR routing protocols are adopted in the research.Moreover,the channel BER(Bit Error Rate) is taken into consideration.Extensive simulations are made in a specifically scenario where nodes move randomly.The simulating results show that routing protocol,traffic intension and the BER are all main factors that affect the optimal UDP packet's length.When considering an error free channel,the optimal UDP packet's length corresponding AODV is a little shorter than that corresponding DSR,and it becomes longer when the traffic intension increases.When considering a channel with BER equaling to 10-4,the optimal UDP packet's length is shorter than that under error free channel,and network performance becames worse quickly when the packet's length increases from the optimal value gradually.