The MAC-Frame is the main input on a 802.11 Protocol Analysis, read and interpret properly the information within a MPDU = MAC Header + MSDU = MAC Frame
802.11v allow the AP's to suggest the clients to roam to a specific AP or give a list of preferred AP's to roam. At the end the client decide when to Roam and where to roam.
802.11 packet capture can give you almost any information from the AP's side, the clients side, the RF side. Learn how to check the Maximum Transmit Power using a 802.11 packet capture