I recently was asked by a customer to assist with planning a Ubiquiti UniFi installation in a large church auditorium. The customer wanted to be able to support the maximum number of users in the large open area that seated 5,000 people. The challenge with this type of installation is that you do not have the benefit of walls to block signal from adjacent AP’s. What I mean is that if you want to limit the number of users to say no more than 50 per AP, this means you would need 10 AP’s to handle 500 concurrent users. That itself is not an issue but 10 AP’s in the same physical room with only 3 non-overlapping channels in the 2.4 GHz spectrum is an issue. If these AP’s were say 3 to a room with walls between the rooms, the challenge would be much easier because the walls would block enough signal (hopefully) to not cause self interference. In this application, that was not an option.
Our approach was this. First, accept slightly overlapping channels for the 2.4 GHz AP’s. This has been done for years on WISP towers and it isn’t optimal but it is workable. In this scenario, we put 4 AP’s on channels 1-4-7-11. There is a few MHz of overlap and self interference but we also have increased our number of users to a total of 200 now or 50 clients X 4 AP’s.
Next, we elected to use UniFi AP-Pro’s since they employ dual band, 2.4/5 GHz radios. The assumption is dual band capable devices will use 5Ghz if available over 2.4 GHz.
So, that leads me to the real purpose of this post. I wondered how many channels the UniFi AP-Pro will support. I searched the wiki, the manual, and nowhere could I find that documented. Now that I have written that, I am sure someone will point it out to me. So, to get the answer I had to power up a UAP-Pro, allow it to be adopted by my UniFi Controller and presto I had my answer.
A total of 9 channel are supported on 5GHz with the Pro’s. So, we configured 5 AP’s to use the bottom 5 channels and the 2.4 GHz AP’s with the upper 4 channels for a total of 13 radios which we hope will support at least 50 users each for a total of 650 users in one room. Will this work? I hope so! I will let you know.