Depends on multiple factors. Ideally you want a wired connection directly to your router, with no other person using up bandwidth. So being on Wifi will introduce latency, especially when the router is in a different room. You or someone else might be hogging the connections by streaming/downloading stuff, but that's usually not the issue. If you can't run a Cat5 or above cable, try Powerline which transmits the data literally trough your wall sockets. You'll have to make sure the transmitter and receiver are plugged into the same circuit. If you _must_ use wifi, check the back of your pc or console, there could be an attachment for an antenna for better reception. If you're on pc, you could get a pcie wifi card which also comes with antennas, ideally those that you can put on top of your case.