一种避免Random Waypoint移动模型速度衰减的方法

Method of Avoiding the Speed Decay in Random Waypoint Mobility Model

在被广泛使用的Random Waypoint移动模型中,随着模拟的进行节点平均速度呈下降趋势.这样的速度衰减现象对自组网等移动系统的某些时间平均性能评价是不利的,会增加精确分析的复杂性;以结点平均速度在整个模拟过程中保持稳定为前提而得到的试验结论也是不可靠的.本文对速度衰减现象进行了概率分析并证明了它是不可避免的,最后提出了改进的Random Waypoint移动模型iRWP,试验验证iRWP能有效避免了速度衰减的发生.

The stabilization of the average nodal speed was critical to research some performancesr evaluation and analysis of Ad hoe networks by simulation. Random Waypoint Mobility Model suffers from speed decay--average nodal speed decreased until converging to some long-term average. Such decay is unsound for simulations that collect results averaged over time, complicating the experiments, and the assumption that steady-state lasts over all simulation makes the results unreliable, collected before average nodal speed arrives at real steady-state. This paper demonstrates via mathematical analysis that speed decay is in general inevitable deriving some conclusions, and then using them provides an improved model iRWP that can effectively avoid the speed decay.