Wi-Fi is sometimes gone on your cell phone and laptop?

Every now and then the Wi-Fi is gone on the cell phone or laptop who knows how to solve this?

Restart router or move closer to the router or increase the transmission power if not already

Choose a better provider. Take the original: Telekom.

Ok, I'll try that

Have such cheap routers, because the WLAN is simply not stable, causes a fault on the laptop and then you either have to restart the router or reconnect to the WLAN on the laptop.