Authorize wireless access prior to allowing such connections.

WiFi networks pose additional risk because they are easy to access by a wide range of devices and access to them is less restricted by physical location. This risk can be reduced by only allowing authorized devices to connect to wireless networks.

Define the types of devices allowed onto your company's networks and only allow them access to your WiFi. For example you decide to only allow company owned devices onto your WiFi network. You can enforce this policy via a technical control (e.g. Mac address filtering or 802.1X authentication). If you have guests or employees that need to use WiFi you can setup a separate WiFi network for them. Create an acceptable use policy that specifies the usage restrictions for your WiFi network. Think of the acceptable use policy you accept when you access WiFi at a hotel.