Abstract: The study of WLAN traffic characteristics is not only important for network performance evaluation but also imperative for the proper network design，management and control.This paper employs actual wireless data drawn from well known archives of network traffic traces and analyzes second-order scaling properties of aggregate WLAN by using the wavelet energy spectrum.For a majority of the upstream and downstream traffic，the second-order scaling exponents at small time scales are fairly close to 0.5，indicating that traffic fluctuations at these time scales are nearly uncorrelated.Self-similarity of wireless traffic at large time scales（larger 1 s） is stronger.Furthermore，the results show that aggregate WLAN exhibits obvious burst effect at every time scale than the assembled Poisson traffic.The observations and results have important implications for accurate wireless networking modeling，traffic control，and optimization of wireless resources.

摘要： 无线局域网业务流特性分析是网络性能评价、规划、设计、管理和控制的基础。应用小波能量谱方法对真实的无线局域网聚集业务流的二阶尺度特性进行分析，实验结果表明大部分上行和下行的混合业务聚集流在小时间尺度上的二阶尺度指数接近0.5，这说明在这个时间尺度上网络业务流呈现弱相关性，而在大时间尺度（秒级以上）呈现明显自相似特性。通过小波能量谱分析也发现，和Poisson过程相比，无线局域网聚集业务流在各个时间尺度上都具有明显的突发性。研究结果为无线网络业务流的准确建模及网络流量控制和优化无线网络资源提供指导。