Configure Captive Portal and Radius Server for HotSpot

Hello, I want Configure a captive portal whith this logic: 1.- The user log in to my free wifi hotspot. 2.- The user open his browser and load page with an Ad (i am thinking to use an ad server like [login to view URL]) 3.- After "x" seconds the window is refreshed and loads the fields for user and password and if Is the first time to login the user must to suscribe to the platafrom for free. 4.- after evrey 15 minuts the user must tho see a new ad. after see the ad the user can continue browsing without relogin. I found lot of scirpts like WiFiDog, but I need advice to know what is the better to work Thank You!