WLAN signal is not only hoped to be strong enough in work area

but also to be attenuated rapidly in no-work area

so content of WLAN signal cannot be intercepted illegally.This paper proposes a novelty solution of a smart antenna based WLAN Wireless Signal Coverage Control.Firstly deploying three kinds of sensor

including Inter Sensor

Edge Sensor

Outer Sensor.Initializing object values of weight value and received RSSI.Then through the Particle Swarm Optimizer

combinations of beam and Tx powers of WLAN APs with smart antenna will be determined

so that the wireless signals are the strongest in inter work area

are acceptable on the boundary of work area and the weakest in no work area.Simulations and experiments over a prototype demonstrate that the solution achieved significantly the destination of WLAN wireless signal coverage control.