As I said i was not aware of a way to do it, but high end equipment you can do it
Wireless LAN Per-User Rate Limiting Solution
So a quick google found this
How do I configure Bandwidth Control / IP-QoS on TP-LINK wireless router
So seems you can do it over wireless, how well it works or if it even does not sure - but I doubt your belkin supports such feature.
So to your solution, grab a new wireless router that supports it.. And give it a go.