Hi. I am also having alot of troubles with my wireless connection on PS3. It just started last night. It was working fine for a while.
I would think the conditions in America are they same as UK, where new wireless networks are continually being added in most areas. It is quite likely the channel you have been using is now being used by someone else in your vicinity and is interfering with the signal. Check what wireless networks are in use in your area by downloading Inssider from the link below, install it and use it to find the channels in use in your area. Choose a channel as far from those in use as possible.