Authentication WAP with RADIUS Server

Network Configuration Figure

Dear all,

I currently performing an testing using the above network configuration (Please click on the above link).
On how actually the RADIUS server can authenticate the user who connect to the WAP (wireless access point) in order to use the Internet services?

It is the WAP need to configured? Can I configure the WAP with hostapd? For the testing I need to authenticate with WEP first.

Please assist.