How do you Control Bandwidth usage over a wireless network?

I have 2 students and they Hog the Bandwidth to the point where it takes me 10 seconds to load a web page or when I'm on Xbox I lag constantly, but for some reason they are able to video chat to they're home countries no Lag at all every day. It's very irritating especially when I pay for the internet. I want to know how to Limit they're bandwidth usage and prioritize mine, for my computer and xbox. Also my router is a Actiontec V1000H. Thanks.