TP-Link TL-WA850RE Manual page 17

Relocate
5
Plug the extender into an electrical outlet about halfway between your
router (Host Network) and the Wi-Fi dead zone.
Wait until the (Signal Strength) LEDs are lit. Make sure the extender
is in a location with 3 or more LEDs lit. If not, relocate the extender closer
to the router to achieve a good (or better) signal quality.
Enjoy!
The extended network shares the same Wi-Fi password as your host network,
but may have different wireless network name if you customize the name during
the configuration.
10
Introduction