计算机应用 ›› 2011, Vol. 31 ›› Issue (01): 212-214.

• 网络与通信 • 上一篇    下一篇

改进的基于最大似然的快速拓扑估计方法

王育红1,费高雷2,胡光岷3   

  1. 1. 四川成都电子科技大学 通信学院
    2. 电子科技大学
    3. 电子科技大学 宽带光纤传输与通信网技术教育部重点实验室
  • 收稿日期:2010-06-28 修回日期:2010-08-10 发布日期:2011-01-12 出版日期:2011-01-01
  • 通讯作者: 王育红
  • 基金资助:
    基于图形处理器的高性能计算

Improved fast topology estimation method based on maximum likelihood

  • Received:2010-06-28 Revised:2010-08-10 Online:2011-01-12 Published:2011-01-01
  • Contact: Wang YuHong

摘要: 基于最大似然的网络拓扑估计方法能够获得全局最优的估计结果,优于一般局部最优化和节点对融合方法,但在网络规模较大时存在计算复杂度较高的缺点。首先证明了网络拓扑估计似然函数是单峰的(即只有一个极值)且峰值为最大值;然后利用单峰特征,改进了现有基于最大似然的拓扑估计方法,在最大似然树搜索过程中无需返回到似然值小的状态,降低了计算复杂度。最后,Matlab和ns-2仿真结果证明在不降低拓扑估计准确率的情况下,改进的算法将计算复杂度减少了30%~46%.

关键词: 拓扑估计, 最大似然, 网络层析成像, 三明治包, 马尔科夫链蒙特卡洛算法

Abstract: Maximum likelihood based topology estimation method can obtain globally optimal estimation results, and its performance is better than that of other methods such as general local optimization and node fusion methods. However, when network scale is large, the topology estimation is computationally intensive. To solve this problem, firstly, the authors proved that a network topology estimation likelihood function was a single-peaked function with only one extreme value, namely, the maximum value called peak value. Using the single-peaked property of likelihood function, they improved the current maximum likelihood based topology estimation method. Without returning to a smaller likelihood value state when searching for the maximum likelihood tree, improved method effectively reduces the computational complexity. Finally, the results of Matlab and ns-2 simulations show that improved method cuts computational complexity by 30%-46% without reducing topological estimation accuracy.

Key words: topology estimation, maximum likelihood, network tomography, sandwich packets, Markov Chain Monte Carlo