Internet signal keeps dropping?

When ever i download big files or watch movies online either on my ps3 or mac or even my iphone and ipod, the signal seems to just stay with that system, so for example if i'm downloading a game onto my ps3 i can't do simple tasks on my mac, as the browser just says resolving hosts or detecting proxy settings, any information will be helpful on how to solve this problem, but could i do it myself or is it something i need to get in touch with my broadband provider, i've got the bt homehub 3.0

Move your wireless router at least 6 ft away from the computer.