Setting up single wi-fi AP to cover entire office building

[miker00lz]

Hi, looking for some advice on setting up wi-fi in a fairly large office building my company is moving to. It has two floors. At our current location we have two APs and SSIDs set up to cover the place, but it's really annoying having to switch between networks and losing connection when we do.

When we move, I'd like to get rid of this problem. I was looking at this:

http://www.radiolabs.com/products/wireless/wireless-ethernet-access-point-repeater-O2Surf.php

My thought was putting it near the middle of the building and using a network of long low-loss coaxial N-type cables and splitters to hook in maybe four to eight high-gain omni-directional antennas like these spaced evenly across the length of the building near the lower floor's ceiling:

https://www.cdw.com/shop/products/TRENDnet-8dBi-Outdoor-Omni-Directional-Antenna/1195674.aspx


Am I going about this the wrong way? Will that AP have enough power to run all of these antennas? I have no experience setting up large wi-fi networks, just home networks.

Thanks!!

 

[azazel1024]

Use the same SSID for both access points and let the clients decide which is the better one to connect to.

If it is a "large 2 story building" you'll never get a single access point to cover the whole thing.

"long low-loss coaxial N-type cables and splitters to hook in to maybe four to eight high-gain omni-directional antennas" is an absolutely horrible idea. The BEST coaxial cabling is going to lead to about 1dB per meter of signal loss in 2.4GHz and double that in 5GHz. That is also VERY expensive coax (about $12 per meter), more typical "low loss" coaxial cabling used for Wifi antennas is about 2-3dB per meter for 2.4GHz and 4-6dB per meter for 5GHz.

Then for every antenna past 1 you have connected on a radio chain, you reduce the signal gain by 3dB. You also have some signal loss in the splitter itself.

You also lose signal gain from MIMO if the antennas are spread beyond some vaguely reasonable distance (generally about 1/2-3 or 4 wave lengths. So from about 2-10 inches or so and you'll begin to lose MIMO gains, which are also 3dB per radio chain).

So in effect by spreading things around, you can easily be losing 20-40dB of signal strength. It is completely unworkable.

You need multiple access points utilizing the same SSID and password and call it a day.

 

[Fardringle]

How big (square feet of floor space on each level) is the new building?

As azazel said, if a single normal access point can't cover the area, just use multiple access points placed around the building set with the same SSID and password, and your devices will choose the strongest signal when they connect to the network. If you want true seamless roaming for devices that move around in the office, then you'll need hardware that supports it, like Ubiquity Unifi or Cisco Meraki access points.

 

[miker00lz]

Thanks for the info, both of you! I had a feeling the loss would be too much. Fardringle, the Ubiquity Unifi looks absolutely perfect! A few of those will be exactly what we need.

I don't have exact numbers on the building dimensions right now, but it's about 24,000 square feet.

 

[Fardringle]

Yeah, you'll definitely need multiple access points. A good quality access point might cover about 3,000 square feet in good conditions without walls/obstructions and no other radio interference. For that large of an installation, it would be a good idea to have a qualified contractor do a wireless site survey to decide where the access points need to be placed and how many you need in order to cover the building properly.

 

[azazel1024]

Short of an open warehouse, yes, many, many. With 24k sq-ft if there aren't too many users you could cover it with one central AP if it is completely open. My outdoor AP is covering my 20,000sq-ft backyard with no issues and the actual coverage out to a very weak connection works out to about 4 acres, about 160k sq-ft, but that is with NO obstructions. Even light partitions will dramatically reduce range. One simple 2x4 wall with 1/2 drywall and the rest open will cut range from maybe around 4 acres for a single good AP to about 1/3rd of that...for one light wall.

Interior, if it is rather open, figure you probably need 4 APs to cover that building. If it is multiple floors or not extremely open, figure 6-8APs.

Be careful with Ubiquiti, not all of their access points have zero hand-off ability and some of the ones that are advertised as "coming soon" it has been "coming soon" for >>>1yr. I'd look at Meraki or Cisco for an actual business. Ubiquiti more if you are a home/tinkerer.

 

[Mushkins]

Be careful with Ubiquiti, not all of their access points have zero hand-off ability and some of the ones that are advertised as "coming soon" it has been "coming soon" for >>>1yr. I'd look at Meraki or Cisco for an actual business. Ubiquiti more if you are a home/tinkerer.

As far as I know, it's only the AC versions that don't have zero-handoff, and even without zero-handoff they will do exactly what the OP wants.

I've got Unifi units across 3 offices, they've been rock solid for nearly 3 years with no handoff or coverage issues. They're completely acceptable for a business-class unit unless your wireless infrastructure needs to be top of the line with all the bells and whistles for a legitimate business reason. No way would I buy Meraki or Cisco units at 3x the price just for general office wireless.

 

[JoeMcJoe]

Thanks for the info, both of you! I had a feeling the loss would be too much. Fardringle, the Ubiquity Unifi looks absolutely perfect! A few of those will be exactly what we need.

I don't have exact numbers on the building dimensions right now, but it's about 24,000 square feet.

Plan on getting over 10 APs.

Zero hand off isn't needed.

Get the UAP-AC-Lite or UAP-AC-PRO models.

 

[Makaveli]

If you need support also you may want to consider a Cisco meriyaki access point.

There is a license fee for it but its enterprise grade the support is great if you don't have someone onsite with all the networking knowledge.

I actually got a free Meraki Access point with a 3 year license from just attending a Cisco webinar. Also got a Layer 2 switch same way.

 

[Fardringle]

If you need support also you may want to consider a Cisco meriyaki access point.

There is a license fee for it but its enterprise grade the support is great if you don't have someone onsite with all the networking knowledge.

I actually got a free Meraki Access point with a 3 year license from just attending a Cisco webinar. Also got a Layer 2 switch same way.

Be careful with the lower end Meraki stuff. Their management system is great and their higher end equipment is very good, but the cheaper access points are really wimpy. I got the same free AP from a webinar and have used it for light access now and then, but even a single Netflix stream (not even HD) will overwhelm it...