多跳移动Ad Hoc无线网络中UPMA协议的仿真

基于有效竞争预约接人、无冲突轮询传输的思想,该文改进了支持节点移动性和多跳网络结构的依据用户妥善安排的多址接人（UPMA）协议,然后利用网络仿真工具OPNET构建了UPMA协议的仿真框架,并仿真了由自组织分群算法所获得群的群内无线传输情况。该仿真框架为UPMA协议详细配置了物理层和数据链路层模型,可以设置不同的信道特性以及应用场景。在此基础上,该文分析了UPMA协议的信道吞吐量、平均消息时延和平均消息丢弃率,并将其与带冲突避免的载波侦听多址接人协议（CSMA／CA）、轮询协议进行了性能比较。仿真结果表明,UPMA协议可以提供较高的吞吐量、较低的平均消息时延和较小的平均消息丢弃率。

Simulation of UPMA Protocol for Wireless Multihop Mobile Ad Hoc Networks

Based on the concept of contention reservation and polling transmission, an improved user - dependent perfect -scheduling multiple access (UPMA) protocol for supporting node mobility and multihop architecture in wireless multihop mobile ad hoc network is described. By using OPNET, the simulation framework of UPMA protocol is developed to simulate wireless transmission in a cluster of wireless multihop mobile ad hoc networks, which is obtained by self- organizing algorithms. With the detailed model setup for physical layer and data link layer, this framework can simulate the performance of UPMA protocol, such as channel throughput, average message delay, average message dropping rate by configuring various channel properties and application scenarios. The performance comparison of UPMA protocol with CSMA/CA and polling protocols is presented. Simulation results show that the UPMA protocol can overcome the disadvantages of the CSMA/CA and polling protocols, and achieve higher throughput, lower average message delay and less average message dropping rate.