Please follow the steps below.
To access your router type http://192.168.0.1 in your web browser address bar.
You will then see the Tplink login screen.
username : admin Password : admin
step1: click the Wireless settings menu
step2: wireless channel, this should set to auto or you can manually select a channel until find your best channel
step3: Change from AUTO mode to 802.11bg mixed
step4: Press ok then reboot the router
step5: wait 1 min and test your connection.