I've had similar dropout issues with a pair of TP-Link powerline adapters. Every so often they drop for 1-2 minutes and then return. Always seems to occur when I'm browsing as I've never had an issue gaming.
I didn't manage to find a proper solution, but some googling indicated that it may be a power-saving function kicking in. Maybe your adapters have something similar?
	
		
			
		
		
	
				
			I didn't manage to find a proper solution, but some googling indicated that it may be a power-saving function kicking in. Maybe your adapters have something similar?
	
 
.  Any other hardwired devices? Do they have the same issue?