08-14-2015 04:08 PM - edited 07-05-2021 03:46 AM
We had originally decided to deploy 4 3702i access points into a new "multi-purpose room". The solution worked well in testing with a dozen or so users. Today, I was surprised to find that they had fit over well over 200 managers and execs into this 60x60 space toting laptops, smart phones and tablets for a presentation. I am now tasked with determining how to improve wireless capacity in the room without introducing interference issues by having too many live APs in the room. We have two Cisco 5500 wireless controllers managing our wireless infrastructure.
This is new construction, drywall over aluminum studs. The APs are mounted to the drop-ceiling about 14ft from the floor. There are no obstructions, the room is used as one large open space with chairs or divided into 4 spaces with retractable walls. The existing APs are mounted in the center of each quadrant of the room (about 15ft from the wall). All APs company-wide broadcast the same SSIDs (Office and Guest). Coverage in the rest of the building (including the hallway immediately outside of this room) is very good.
1) Is the 3702i the correct AP for the job?
2) How many is too many in this space? I'd gladly install 12 more if it meant never having to deal with this issue again.
08-14-2015 04:22 PM
1) Is the 3700e the correct AP for the job?
For indoors (and 14 ft above), I'd prefer 3702I.
2) How many is too many in this space? I'd gladly install 12 more if it meant never having to deal with this issue again.
There's a fine line between putting more APs and having too many APs that half of the APs will power down. Get a wireless site survey done if you want this done correctly.
08-17-2015 07:24 AM
My mistake, they are in fact 3702i not e.
I've corrected the title and body of my question.
08-16-2015 10:32 AM
There's a lot we don't know about this scenario. What are the throughput capabilities of the clients? What kind of apps do they need to run in this space? Will each person run more than one device at a time - if so would you assume 250 users with two devices that need simultaneous access (500 devices max)? Are you keeping the existing AP's or replacing them with the 3702's?
Without an active survey and just doing basic capacity planning I would estimate a requirement of 12 radios, meaning 6 dual-band AP's evenly spaced if the room is perfectly square. 60x60 is not a large space but we're planning for high density, not RF coverage. I would reduce power on your AP's to keep cell sizes smaller, increase the minimum data rate requirement for these AP's (something around 36Mpbs on both radios as a starting point). Put them in an AP Group on your WLC for ease of management.
I would prefer the 3702i model simply because it's an indoor AP. Unless you need a directional antenna there seems to be no reason to do anything else.
Be careful of those retractable walls - they will usually kill a wireless signal when extended so be sure to have enough AP's in each section assuming that all of the retractable walls are fully extended. Net result would be 4 spaces that need coverage, not one large space.
08-17-2015 07:22 AM
The users are all managers and execs, every device on their person will have a connection to Exchange but I wouldn't expect anything heavier than email and light web surfing while that density is present. I'd expect a mix of smartphones and iPads and number of HP laptops. I would not expect anyone to carry more than two active devices.
The 4 existing APs in that room are the 3702i; I deployed a total of 34 3702i and 6 1532s at that site. I designed the facility's WiFi as a classroom environment since it is a training facility for electricians. Coverage and performance is excellent in all areas with the exception of that unexpected dense gathering. The 1532s worked very well in outdoor and semi-outdoor training areas where the instructor uses a tablet or iPad.
I don't see much value in a survey. It's big square room with chairs arranged in lines from wall to wall with a small space around the perimeter and an idle up the middle. I can't predict who will sit where or do what at any given meeting and the large gatherings are infrequent. It's a "multi-purpose" room, they will use it for gatherings of 10 to 20 per quadrant most of the time (thus the single 3702i mounted in the center of each quadrant).
It sounds like it is worth adding 1 AP to each quadrant and making the power / MDR changes that you suggested. I have at least 4 spares in the store room. I won't have results until I can get that many devices in the room again.
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