A:Answer If you are getting a poor signal only one floor away, you probably have an old or low end router. To keep things simple, I'd recommend first updating your router. I just switched to the TP-Link AC4000 and installed it in the basement. We get a strong signal on the 1st and 2nd floor. Our TV and Roku are on the 2nd floor and have no trouble streaming 4K from Netflix and YouTube. Absolutely no stutters or breaking up. The iMac on the 1st floor works fine as well.
Exception: some communities have a fire code that requires a metal fire barrier between floors. No WiFi system can broadcast through that. In that case you'll need to run Ethernet cables between floors. A concrete fire barrier shouldn't cause a problem.
We also get a good enough signal for our Tesla which is in an attached garage to the side of the house. But AUTO for channel selection didn't work, had to switch it to Channel 1 for the 2.4 GHz band and 36 for the 5 GHz band. Now the Tesla connects and updates fine.
SSID tip: use the same SSID for the 2.4 and first 5 GHz channels and a different SSID for the 2nd 5 GHz channel. If all 3 are set to the same SSID then devices will only use the 2.4 GHz channel. The idea behind having two 5 GHz channels is to dedicate one to a specific function such as gaming where it doesn't have to compete with other devices.
BTW, perhaps due to the great deal on the new TP-Link Wifi 6 router, the AC4000 is on sale.
