my router is on the 2nd floor of my house and im on the 3rd floor. the wifi is so slow at my floor then it takes me like 3-4 hours to download a 30 gb game ( Overwatch).But on the first floor when i downloaded overwatch it took me 30 minutes.When i get into a game my wifi is not constant and keeps changing .Some minutes its 20 ping in the game but now mostly its 150-300 ping average and it goes up to 600-800 ping with 40-60% loss of wifi .I did a speed test and the results keep changing too .First test to a local server under speedtest.net said my ping is 7ms, upload speed is 4.87 mbps and download speed is 6.43 mbps.2nd test said i got ping 8ms, download speed is 11.73 mbps and download speed is 6.58 mbps. I did the wifi speed test on my desktop on the 3rd floor.My question is why does the wifi vary on each floor ,why does my wifi speed keep changing , is LAN cable recommended to make the internet speed more constant??