I believe the controller is required if you want to use vouchers (as the vouchers are generated by and validated by the controller; the access point just acts as a "middle man" between the client and the controller). If you don't want to have an EAP controller on-site, you can set it up on an AWS instance or other Windows VPS and manage it from there.

DocJones wrote

I believe the controller is required if you want to use vouchers (as the vouchers are generated by and validated by the controller; the access point just acts as a "middle man" between the client and the controller). If you don't want to have an EAP controller on-site, you can set it up on an AWS instance or other Windows VPS and manage it from there.

Ok thank you, roughly how much do you think it would it cost to host on an AWS instance?

You're looking at ~$6/month for a t2.nano (1 CPU, 512MB RAM) instance with Windows, or ~$13/month for a t2.micro (1CPU, 1GB RAM).

Another possible hosting provider might be OVH.com if you're looking for something beefier; their "VPS Cloud 1" option is $14/month and is beefier than a t2.micro with 1CPU and 2GB RAM for a bit over a dollar more. Atlantic.net has an offering closer to the t2.micro (1CPU/1GB) but it's the most expensive of the three at $15/month.

Keep in mind these will probably be lethargic, as even the server OS isn't so thrifty with memory that 512MB or 1GB will be terribly comfortable. Throw the Java engine on top of it and it will still work, just not super fast. The 1GB might still manage decently (mine is running on 1GB and is a bit slow but not awful) but my instance's CPU usage shows 619MB so the 512 will be hitting swap.