Wifi in the auditorium

[kYutobi]

Hey guys,

Just need some opinions. So we have a community meeting where we are maybe 180 in an auditorium where I have two MR42's in place. Granted I've never had any issues before but want to know if 2 APs is considered "ok" for that volume of people. There's a simple survey we are going to do and I don't think 100% of the 180 will bring their laptops.

Any thoughts?

• I know that safe spot usually is 30 clients per AP

[PhilipDAth]

Are the APs roof mounted and if so how high is the roof?

[kYutobi]

@PhilipDAth I would say 20ft. on ceiling.

[kYutobi]

@jdsilva any thoughts as well? 

[jdsilva]

---

@kYutobi wrote:

@jdsilva any thoughts as well? 

---

Actually, nope. I'm not much of a WiFi design guy... I leave this stuff to people much smarter than me. 

[kYutobi]

@jdsilva lol thanks for honesty. Don't act like you're not smart 😂

[vassallon]

@kYutobi What are these 180 people going to be accessing or possibly accessing? That will also be a factor into how many APs you may need. Always remember that 180 people with a known device has the potential to be 360 devices when you account for phones depending on the WiFi setup.

[BrandonS]

I can only say, maybe.  It depends on soma things.  From experience with these types of spaces I can tell you that you should not install MR's up high on a ceiling (like 20+ feet) and try to get them on walls around 6-10 feet high.  As someone else noted, if 180 people show up they will likely have other things like fit bits, watches, tablets, etc., etc.  If you plan to limit bandwidth and set expectations properly 2 could be enough, but I would probably budget for 4 without knowing more or doing any kid of survey.

There is a cool tool to help understand designing for capacity vs. coverage here that might be helpful: http://www.revolutionwifi.net/capacity-planner. It is not Cisco or Meraki specific, but it was created by a well respected wireless CCIE.

[kYutobi]

@BrandonS thank you for the insight.

[PhilipDAth]

I'm guessing this is an existing deployment, so this wont be helpfull ...

Meraki make a couple of external antennas for this kind of deployment.  The one that suits roof mounting below 25ft is this one:

https://meraki.cisco.com/products/wireless/antennas-power#MA-ANT-3-E5

I would use the auditorium RF profile (which will configure 20Mhz wide channels and raise the minimum bit rate):

https://documentation.meraki.com/MR/Radio_Settings/RF_Profiles

I would use a minimum of 2 x MR53E's, or 4 x MR42E's.  Note that an MR53 can handle twice as many 20Mhz clients as an MR42 (simply because it has twice as many radios).

[kYutobi]

@PhilipDAth @BrandonS @vassallon Much appreciated guys. I will definitely let you guys know what happens and if I reach any snags. Hopefully there will be no hiccups.  

[kYutobi]

---

@vassallon wrote:

@kYutobi What are these 180 people going to be accessing or possibly accessing? That will also be a factor into how many APs you may need. Always remember that 180 people with a known device has the potential to be 360 devices when you account for phones depending on the WiFi setup.

---

As far as phones go @vassallon they can only connect to guest which bandwidth is shaped to about 1 meg. Not all 180 will be accessing I just know that's about the number.

[vassallon · Accepted solution]

@kYutobi The issue isn't necessarily that the additional devices are even connecting to WiFi but adding more noise to your environment as well. 

As for demand, 180 clients connecting to a mostly text website or such will be much lower than 180 clients connecting to a live stream, video presentation, etc. 

@PhilipDAth Suggestion of more APs is great but without knowing exactly what the demand is, makes planning quite hard.

[kYutobi]

End result. We had 124 clients on one AP and 104 clients on the second.  They are just doing a survey fyi. I had one user who had a little lag but when I refreshed browser she was ok again. I did however do a little bandwidth shaping on the SSID I have for teachers. It went very well and it's good to see that even with that volume of users Meraki can handle the load.

Thanks @vassallon @PhilipDAth @BrandonS for all the help/advice/input.

[vassallon]

@kYutobi That is great to hear, we've had one MR42 to use for testing some of the strange network behavior we've had and it's a solid AP. Which version of firmware are you running on it? I know with the 26.2 release we have seen much better performance with the MR34s under heavy loads (40+ clients.)

[kYutobi]

@vassallon 25.13