Abstract: Detecting intrusion attacks accurately and rapidly in wireless networks is one of the most challenging security problems．Various types of intrusion attacks can be detected by the change in traffic flow that they induce．We proposed an intrusion detection system for WIA-PA networks．After modeling and analyzing traffic flow data by time-sequence techniques,we proposed a data traffic prediction model based on autoregressive moving average (ARMA) using the time series data．The model can quickly and precisely predict network traffic．We initialized the model with data traffic mea-surements taken by a 16-channel analyzer．Test results show that our scheme can effectively detect intrusion attacks,improve the overall network performance,and prolong the network lifetime.

Key words: Wireless network,Network attack,Traffic prediction,Autoregressive moving average