Hi Cider,
I'll start with the easy question. If you have no trouble with your wireless network at the moment, there's no need to purchase an additional antenna. The only thing that this would do is increase the strength of the signal.
As for MAC address filtering, a MAC address is the physical address of your network card. I'm attaching a screenshot with a sample. It's the number highlighted with the red box. Each network card in the world has a different address. The first part actually identifies the manufacturer, followed by a unique identifier.
If you connect to your wireless router, you should have an area in the security setup for "MAC address filtering". In this, you would specify the addresses of your network cards. As a result, only cards with those addresses will be allowed to connect.
Let me know if you need more info.
Cheers,
BrainStop
Reply With Quote