基于拟生灭过程的多跳Ad hoc网络洪泛方式下拥塞控制及饱和条件研究  

Congestion Control and Saturation Condition in Multi-hoop Ad hoc Based on Quasi-birth-and-death Model

作　　者：夏文洁[1] 李千目[1] 刘凤玉[1] 孙晋厚 

机构地区：[1]南京理工大学计算机学院,南京210094 [2]二炮装备研究院,北京100085

出　　处：《计算机科学》2012年第4期110-113,共4页Computer Science

基　　金：国家自然科学基金(60903027)资助

摘　　要：802.11Ad hoc网络中拥塞控制是保证网络稳定性的重要因素。拥塞发生时,通常的做法是控制流量,而研究网络何时出现拥塞则是目前的首先任务。针对多跳Ad hoc网络,对单个节点的数据发送过程,考虑包的最大重传次数、数据包的缓冲队列,提出一种新的基于802.11MAC接入协议DCF Basic Access机制的无限状态拟生灭过程模型。研究了在洪泛方式下为避免网络到达饱和状态,节点MAC层上数据包的到达率应满足的条件。指出在DCF协议下到达率对网络状态的影响。与现有文献的区别是,从网络层的角度进行研究,提出了一种新的更精确地描述数据发送过程的模型。给出了多跳Ad hoc网络中稳定性与数据到达率的数学关系式,为多跳Ad hoc网络的拥塞控制提供了一个重要的参考。Congestion control is an important factor for the performance of IEEE 802.11 in Ad hoc wireless network.When congestion occurs,the packet rate is controlled,and researching what time congestion exists is a primary task.This paper performed researches on multi-hop Ad hoc network by modeling the packet sending process of individual node.Considering packet maximum retry time and packet buffer queue,and on the basis of 802.11 DCF basic access mechanisms,the paper proposed an infinite state quasi-birth-and-death model.By solving the model,the research on how to prevent saturated network under flooding mechanism was performed and corresponding formula which involves the packet arrival rate on MAC layer was obtained.The impact of packet arrival rate on stability was pointed out.This is fundamentally different from earlier work,which usually focuses on the DCF mechanisms itself,while we from the network layer view proposed a new model which accurately describes the actual packet transmission process and formularizes the mathematical relationship between the stability and packet arrival rate,which provides a mathematical tool for congestion control research.

关 键 词：拟生灭模型 802.11DCF Ad HOC 数据到达率 洪泛 拥塞 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]