Networking iOS devices via wifi - max number of connections?

Hi to all,

I'm using iOS devices, networked via wifi, for music installations. I've already done it with 5 devices in an exhibition, and tested with up to 7. If the server is an iPad 4, how many devices can I connect to it reliably ( without losing connection for 10 hours non stop )? I use a dedicated router ( airport extreme ), and network via Unity's API ( but use Bonjour for service discovery ).

I'd love to test myself, but it's not that easy to get 12+ devices at my disposal for enough time to try things out.

Any insights very much appreciated!

Gregzo