We got our first bunch of 15 MR33 yesterday, we are going to put them in office and work shop. office is considered as open area in most area, workshop has a lot machinery which may block the signal. so I would like to have some general information about the distance between the AP for a better coverage and less interference.
Many thanks in advanced for any suggestion.
There is no rule of thumb for recommended distance between APs. There's the basic "1 AP per 25 client equipment’s" but I strongly suggest a site survey, focusing in which are the main areas you want/need coverage and what type of service would use the network (like just simple data or there would be voice services with roaming clients?).
And also check which interference is generated by the workshop machines and other sources of RF interference (microwave ovens, motion/alarm sensors, neighbor rogue APs, etc).
At the worst case scenario, if you don't have a RF spectrum analyzer or budget to pay for a Site Survey, you can install a MR33 and check the RF Spectrum status but if you want to pinpoint interference sources, you have to run a survey with a spectrum analyzer.
That shouldn't be a problem because, by default, they would set themselves to non overlapping channels.
As for free RF Spectrum... "if you pay peanuts, you get monkeys"...
Ekahau HeatMapper is just for wifi signal, it's not a RF spectrum analyzer. For that you'll need a Ekahau Sidekick or a Netscout Airmagnet. Here's a nice video comparing the different RF spectrum analyzers:
Head to Head comparison of Spectrum Analyzers | Keith Parsons | WLPC_EU Lisbon 2017
As I told before, Meraki AP's have an integrated RF Spectrum analyzer (you can check it by going to wireless -> rf sprectrum -> click on AP name) but it would be dificult to carry one around in order to pinpoint an interference.
We have 92 access points in a school, and had lots of problems with the default settings (auto) because they interfere with each other and keep changing channels. Calling Meraki support, they said it should never have been set up on auto, they should have fixed channels and specific power settings on all access points. So the company that installed them had to come back in and re-survey, make a channel plan so they didn't overlap, and set the power to manual on every access point. Things work much better now.
@R_Artes ; for that amount of APs, sure.
What I usually do is to manually configure the 2,4 channels on the central APs and let in auto those that detect a lot of neighboring rogue APs so they can avoid the external interference as much as possible.
And as long as the APs are mapped correctly during the installation, it's possible to adjust the channels without going on site.
My usual procedure is to install the APs in auto, let them negotiate their channels between them and the neighboring APs and, on the next day, check the channel map and make the necessary adjustments. Obviously, the procedure is only concluded once the local users confirmed if they are pleased with the coverage and network performance.
The interference will only be an issue if the two APs are using the same channels. If you keep your APs using auto-RF or ensure that each AP is using a different channel, you shouldn't see an issue with interference. 2.4GHz obviously is a problem child because it only has 3 channels to use. 5GHz has many more, so the chances of cross-channel interference is lower.
In our workshops, open with high ceilings but a lot of metal etc... we place them about 75' apart. We typically mount them around 15' off the ground facing down depending on what options there are from the ceiling.