Which device makes the roaming decision for a wireless client?

The wireless client makes the roaming decision. It continuously scans for stronger signals from other access points (APs) and decides when to disassociate from its current AP and associate with a new one. This is a client-driven process. The wireless LAN controller (WLC) manages the APs and facilitates the roaming process by providing necessary information, but it doesn't initiate the roam. The access point (AP) provides wireless connectivity but doesn't decide when a client should roam. A WCS (Wireless Control System) location server is used for tracking client locations and network management, not for making roaming decisions.