Can the new AP541N's be used to expand the wireless coverage area for a small business using UC540 with integrated wifi? There seems to be some confusion about what is possible and supported. This would be for voice over wireless use.
The AP541 is specifically designed with the UC5xx platform in mind. It has been carefully molded to fit with a variety of Small Business Pro devices such as the ESW switches, SA5xx firewalls, SR5xx routers, and of course the UC5xx platform.
Here is a great link to what you inquiring about :
In it, the question you asked is specifically addressed. You can also take a gander at the Admin guide here:
It goes into greater detail about how to set up all of the features of the AP541.