is someone accessing without authorization?

How do I know if someone is accessing my wifi network. I could see his mac, IP address, rx/tx rate(with activity, could see numbers changing) in the hotspot hosts list but I could not see him trying to log in, or see him in the active list.

I am not good in networking. I am just starting out. I am worried about my network security.

How do I know if someone is currently using/accessing my network?

I always see several devices that are connected to my wireless hotspots, and never use the service. But every time they show up here (tourist area), I see they connect and do not try to login. The update checkers in their computer don’t know that, so they try to get Microsoft updates, anti-virus updates, Adobe and Java updates, hardware driver updates, etc. If your hotspot is set up correctly, you should not have a problem.

ADD: If you want to check, use torch to see if the traffic is going out an interface. Bear in mind that DNS requests may go out over the wan interface, even if the client is not logged in.