一种节点自分布最优Ad Hoc多播树及其应用

为无线单播模式设计的RTS/CTS信道握手机制不适用于多播模式,导致Ad hoc多播树节点易与隐藏终端发生冲突.通过提出m阶冲突域、节点在冲突域中的分布指标,结合无线网多播数据通信机制分析树节点所在m阶冲突域的冲突概率,进而得到节点自分布最优树的概念,并将它融入多播树的适应函数的设计中,淘汰不良树,优化树节点在m阶冲突域中的分布,在网络层形成一种预防机制,可降低隐藏终端冲突概率;应用于MAODV协议中,提高了MAODV的端到端数据分组平均投递率,这也能够为基于网的和混合式的其他类型MANETs多播路由协议的路由节点分布优化提供有价值的参考.

A Node-Self-Distribution Optimal Ad Hoc Multicast Tree and Its Application

RTS/CTS handshake mechanism is especially designed for Ad hoc unicast mode but not for multicast mode.This leads Multicast tree nodes prone to collide with hidden terminal(HT).The m-rank collision domain,the distribution of nodes in m-rank collision domain indicators and the concept of nodes-self-distribution optimal tree(NSDOT) are proposed while the collision probability of tree node in the m-rank collision domain is analyzed considering the wireless network data multicast communication mechanism.They are integrated into the design of the multicast tree fitness function to eliminate bad trees and optimize the distribution of tree nodes in the collision domain of rank m.A preventive mechanism in advance is formed at the network layer,which reduces the collision probability of HT.As an application in MAODV,the simulation results on NS2 show that NSDOT obviously and stably increases the average ratio of data packet delivery.These can also be a valuable reference for the routing node distribution optimization of the mesh-based,the hybrid and the other types MANETs routing protocols.