Wireless Connection Process

Below is the process a wireless client goes through in order to get access to a wireless network:

Step 1 - Start
This is the initial connection between the client and AP. This is where L2 security authentication and encryption mechanisms are in place, for example: none, static WEP, 802.1X, WPA / WPA2.

Step 2 - DHCP
L3 operations start here, an IP address is attained as well as L3 security elements, such as authentication via a webpage at a hotspot. This could be the first phase if L2 security isn't configured.

Step 3 - Mobility
The clients final IP address is applied here and it can fully function at L3. The address could have well changed here from step 2 if web authentication was used.

Step 4 - Run
The client is live and sending data.

Layer 2 security comprises of:
Authentication - 802.1X or PSK
Encryption - None, WEP, WPA or WPA2 (TKIP or AES)