Wireless client roaming decisions are made by the client device based on its own criteria, such as signal strength, noise level, data rate, etc. The network can influence the client’s roaming decision by providing information such as neighbor reports, load balancing, band steering, etc., but the final decision is up to the client.References:https://www.arubanetworks.com/techdocs/Instant_86_WebHelp/Content/instant-ug/wlan-roaming/client-roaming.htm

Wireless client roaming decisions are primarily made by the client device itself. The client device monitors the signal strength and quality of the current connection and decides to roam to a different Access Point (AP) when the current signal deteriorates below a certain threshold or a better option is available. While APs and controllers can provide information and support for roaming decisions through protocols like 802.11k and 802.11v, the ultimate decision to roam is made by the client device based on its algorithms and thresholds.