Whi isn't my Wi-Fi working on my iPod Touch 4th generation?

So yesterday I was using the internet and the apps that require internet on the iPod and everything was fine. Comes later on that night thw Wi-Fi cut out. I didn't understand why and I still don't understand. I turned the wi-fi off, unplugged the router, and I even resetted the network on the iPod and nothing worked. Well it works when I'm directly in front of the router but if I move to the basement or something the internet is gone. How do I fix this? Should I restart the whole iPod?