TP-Link TL-WA855RE User Manual page 19

3.
Select the network you want to extend from the list.
If the network you want to extend is on but not shown in the
list, please try the steps below.
Move the extender closer to your router. Then click

Refresh on the top-right corner of the list to scan the
network again.
You can also enter the SSID and password of the network

you want to extend on the Connect to Network page.
Then click Save to connect to the host network.
4.
Once a network is selected, the SSID and security settings of that network
will automatically be filled in. If the host network is encrypted, enter the
password and click Save.
When Host 2.4GHz Security is WEP, please select the index
same as the host network.
5.
Relocate
Plug in the extender halfway between your wireless router (Host Network)
and the Wi-Fi dead zone.
Wait about 1 minute until the LED is lit with a solid green. If not,
relocate the extender closer to the router to achieve better signal
quality.
Enjoy!
The extender shares the same wireless network name (SSID) and wireless
password as your host network. If you want to change the wireless network
name (SSID), please refer to Customize the Extended
Manage the Extended Network and Security Settings
SSID.