How can I get better Wi-Fi signal in my house?

David is having issues with his Wi-Fi upstairs. Leo says that if he's using the router from his ISP's modem, he should turn off Wi-Fi and get his own router. That often will solve the problem. He should make sure he has a DOCSIS 3 modem as well. In fact, while he's at it, he should just buy a modem as well. That way he will save the monthly rental fee he's paying his ISP for that modem.