Aruba 501 Bridge Configuration

I posted previously about bridging our Wifi to an outbuilding and I thought it was working fine, but some wireless clients cannot stay connected.

The basic setup is:
`WAN -> (A) Aruba IAP-205 -> (B) Aruba 501 Bridge <--> (C) Aruba IAP-205`

ISSUE:

1. The WAP (C) in the outbuilding does not join the WLAN Virtual Controller for the main building.

ASSUMPTIONS:

1. Wireless clients probably cannot stay connected because they're trying to connect to the main building APs, which are too far away for the weaker antennas.
2. The Aruba 501 bridge is NOT a Wifi Extender/Repeater/WAP.
3. I only need 1 Station Profile set up on the 501 Bridge because it provides an upstream connection; it's not setting up a WAP.

POSSIBLE SOLUTIONS:

1. Create a new SSID for the outbuilding and add this profile to all managed devices.
2. Duplicate the main building's SSIDs and hope they don't conflict.
3. Change hardware arrangement?