Question: how to know who is using my wifi tp link?
Answer: Go to your router settings through any browser, either on your PC or smartphone. Typing out 192.168. 0.1 (for TP Link router) or 192.168. ... 
Login using your username and password. The default is : ... 
TP Link : Go to Wireless > Wireless statistics. D-Link : Go to Status > Wireless Clients.