Need advice on the following:

We have 3 devices:
Server A (via AP)<-------------->Device B<--------------------->Device C

Device B and C each has a wireless interface (running QNX inside). Device B and Device C operates in a vehicle and 
communicate with each other using wireless-a. When the vehicle goes to a certain location, Device B needs to communicate
 with Server A (also using wireless-a). Server A is in a fixed location and talks to Device B via an Access Point. All 
wireless communication will be protected using WPA.

We intend to run Device B in Host AP mode. Device C shall act as a client when talking to Device B. Our question is: 

Can Device B (which is already in Host AP mode)  also act as a client and communicate with Device A? While Device B 
communicates with Server A, the wireless comms between B and C should not be affected. Is this possible?

I hope my description above makes sense to you. Please kindly give me your advice. Thanks!