802.11b中业务源基于隐马尔可夫的测量与分析

Measurement and Analysis on Traffic Source in 802.11b Based on Hidden-markov-model

出于经济方面的考虑,分析通信系统中的频谱资源并对其进行建模是极其重要的。在大多数时候,能通过空口测量来捕获各类无线通信系统中授权用户的业务参数,从802.11b的物理层结构开始研究,建立相关的隐马尔可夫模型(HMM)。为了分析业务源的行为,使用BW算法来估计业务源的参数,而业务是用D-ITG软件来产生的,因此可以将结果与真实模型进行比较。实验结果表明,在802.11b协议下,使用隐马尔可夫模型和BW算法来对信道占用行为进行模拟是不准确的,但是分析业务源的特性是可行的。

In view of economic factors,the analysis and modeling for spectrum resource in communication system are always important.In most of the time,the traffic parameters of authorized user can be gotten through air interface measurement. Firstly the physical structure of 802.11 b is studied,and then the model based on Hidden-Markov-Model（ HMM） is built.To analyze the behavior of the traffic source,the Baum-Welch algorithm（ BW algorithm） is used to estimate the parameters of traffic source.The traffic is generated by using software named D-ITG,so it＇s practicable to compare the model result with the real one. The experimental results show that,in 802.11 b,using HMM-based model and BW algorithm to simulate the channel occupancy behavior is not proper,but it is feasible to traffic source characteristics analysis.