What are the steps for creating a  pairwise master key (PMK)?

What will be an ideal response?

The IEEE standard defines two ways in which wireless devices and APs can retrieve a PMK. The difference depends on the security model that is being used. If the Wi-Fi Protected Access (WPA) Personal security model or WPA2 Personal security model is being used, then a preshared key (PSK) is entered by a user into both the access point and the wireless device (usually as a passphrase, which can be between 8 and 63 characters). This PSK is then used in conjunction with the service set identifier (SSID) to form the mathematical basis of the PMK on the wireless device as well as on the access point.

If authentication is performed using the WPA orWPA2 Enterprise security model, the PMK is generated by the RADIUS server and sent to the access point. The wireless device,which has already received the PM from the authentication server, will use it to generate its own PMK.