The solution for weak wireless signals upstairs: A USB WiFi adaptor with a 6-inch antenna
This device has worked much better than mesh networks and repeaters.
In my home, the router is located on the north side of the first floor. The signal on the south side of the second floor is very inconsistent. Zoom calls are tricky, because at random intervals, the signal drops. I've tried different approaches to fix it.
Xfinity, my ISP, sells XFi pods. You plug these pods throughout the house to create something of a mesh network. You are supposed to be able to seamlessly move throughout the network without losing a signal. But these devices created other glitches. Consistently, my phone would connect to one pod, disconnect to another, and then reconnect. It was a constant struggle. I got rid of them.
Then I bought a WiFi range extender. I placed it on the south side of the first floor. The signal became stronger on the second floor, but intermittently cut out. I suspect there is some interference with neighboring networks. (There are about a dozen in my immediate area).
My most recent solution seems to have done the trick: an external USB adapter with a six-inch antenna. Now I can connect a laptop upstairs to the router downstairs. So far, the signal has not dropped. This device is not practicable for smart phones or tablets, but it works well for a laptop. I keep it plugged into the USB hub, so I can automatically connect to the network when I plug in. This device is also much cheaper than everything else I've tried. The adaptor is only $17.
Consistently, students complain about weak wifi signals in different part of their homes. This cheap device may provide a solution.