When setting up a wireless connection, some wireless software will prompt you to enter the router's PIN to set up a secure wireless connection.
You'll find the PIN in the WiFi protected settings.
Alternatively, the wireless software may give you a PIN for you to enter onto the router's admin pages - an example of a BlackBerry device has been included below:
In this case, type the key provided by the wireless device into the WiFi protected settings.
If you find you're unable to connect using WPS set up, don't worry. Simply connect by entering the router's wireless password instead.