Before a smartphone can use the Wi-Fi network, it must associate with the network and be validated.

The easiest way to do this is to configure a key on the smartphone. After it is configured and when it comes on the network, or when it roams between APs, the smartphone uses the key to get on the network.

A more secure method is to use an Authentication server (such as RADIUS, IAS, ICS, AAA). Authentication uses the 802.1X protocol to validate the user by using an Extensible Authentication Protocol (EAP) type. There are many EAP types, but they are all similar in that they communicate to the Authentication server before allowing access to the network. While 802.1X and EAP are more secure, they take time to perform the authentication. The authentication can take several seconds and occurs when the device first comes on the network and every time the smartphone roams between APs. If a smartphone is in a VCS call while roaming, there could be several seconds of lost audio on each roam.