Yo-yoing Download speed?

I don't know what exactly is happened but this I have noticed has been happening for a few weeks now since December. It's happened at my old location. And it's happening at my new location. When I download from anywhere I get a good speed. Then it goes up and down. And in some cases my wireless connection gets lost and I have to reconnect. It's so frustrating.

I have a Ubee U10C018 modem hooked up to a Cisco-Linksys WRT110 RangePlus Wireless Router. My ISP is Road Runner/Time Warner Cable.