Mobile Devices Cutting Out Internet?

I have a Belkin Wireless N1 router and it works great with my laptops and desktop computers.But! Whenever I connect up my iPad 2, mobile phone (Nexus S) or any other mobile phone, Apple TV or PS3 - the internet works and then after about 10-15 minutes (maybe more, maybe less) the internet cuts out and I can't connect on any device. The PS3 works great when hooked up through ethernet, but wirelessly the connection doesn't last very long at all. Both my parents and brother have an android based smartphone and when at home they'd like to use our WiFi instead of their mobile data - and when it comes to online gaming on the PS3, I don't want to have to trail an ethernet cable all the way to my PS3 set-up. I have full signal strength throughout the house so range isn't an issue - I've also tried connection up whilst next to the router and the connection still cuts out. To resolve this I have to pull the power cable and re-boot the router.

I have cable broadband and the modem still indicates that I have a connection, and when the internet is cut from the modem the router shows a message saying that "No internet connection can be found". The screen still indicates that it still has an internet connection but it just isn't broadcasting it...I've altered the broadcast channels but this hasn't done anything. I can connect up to my friends Belkin ADSL Wireless router with no problems and it doesn't cut out. He has his PS3 connected wirelessly too and it's all good...