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I work for a multifamily housing developer. We build apartments. In this case, we are building a facility with about 600 beds (~220 separate housing units).

The density is that of a typical apartment complex in a sub-metropolitan area. There are 4 stories in this one I think (maybe 3), and each apartment has its own short-range wireless router. The developer is including wifi in each room, with the equipment already installed and ready to use. A few of the wifi units have been vandalized or damaged, but this costs so little ($75 for a 5ghz wireless router) to replace that we plan to repeat this simple solution in our next 250 unit development.

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The above description is actually somewhat fictitious. In reality the development is rigged with several strategically placed "WAP" repeaters which reside outside of the residents' rooms in the hallways. We've spent well over $300,000 for this equipment and here's the rub---25% of the apartments are unable to connect to the internet using these WAP wifi signals. For the ~75% of units where it works there are no complains, its been described as a problem which "you either have or you don't". There isn't much of a grey area.

The company hired to install & maintain the system is a no-name, regional company (I can't remember their name right now but will include later when I find out), and have been stopping by twice a week, every week for the past month now. They've brought in experts from California & Japan (we're in Georgia) and still have not discovered what exactly the problem is.

My comment and concern after this massive mistake on our part (not delivering internet to paying tenants who've been told internet is included is like not delivering water or electricity), aside from choosing what is obviously an incompetent firm to install the system, is that maybe it is over-engineered for the task delivering the internet to our tenants.

I'm no electrical engineer, but I was thinking (during the meeting that I spoke up about it) that if we simply want all of our tenants to have wifi & all of the units have multiple ethernet jacks, why can't we just manage the whole system through wired ethernet systems for each (metering bandwidth as necessary during peak hours), with the (typical password-protected) wireless component as the last leg of the delivery system?

I've lived in an apartment (which did not directly provide the internet to its residents) and regularly observed >30 wifi networks when I logged in to my own. Not once did I have problems with wifi interference due to the density of separate networks in my apartment area.

So I floated the idea of a this simplified approach on our next deal. I'm told, however, by some of the guys on our construction team (who have been pitched, I think, on this $300K+ WAP-Repeater network) that were we to set up a separate wireless network in each of the rooms of our development, the interference caused by this would be so bad that the residents' internet wouldn't work reliably due to wireless interference.

The density of the apartments is typical for a 3-4 story 150-250 unit apartment development. Its all one contiguous building, but the building is made up of several wings separated by multiple courtyards. I've included an aerial photo of this site complete with some rough dimensions the site

So my question isn't necessarily the one in the header. If you have an answer for that, that's great, but I'm generally just trying to figure out if we've been taken advantage of or not. I've just never experienced the wifi interference that our construction partners have been educated to worry about, and, again, have seen as many as 30+ wifi networks in range when connecting to my wifi network without a single problem...

EDIT: I think this is a video from the manufacturer of the hardware we've been using on the subject of interference. This video is part of a larger series of sales videos that I've recently discovered.. http://www.youtube.com/watch?feature=player_detailpage&v=-6l0--rI8jA#t=166

Mike Pennington
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boulder_ruby
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    Think about what happens if you lower the power output of each access point, add that to intelligent channel choices and I beleive you'll find your solution there. Think of it as being a more localized point. That is -- if it is economically feasible to outfit every apartment with an access point. –  Nov 08 '13 at 00:51
  • By access point do you mean a wireless consumer router or a WAP repeater? – boulder_ruby Nov 08 '13 at 00:54
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    There is no theoretical limit, but there is a practical one, as is the case with many issues. You're probably talking 802.11 b/g/n. The 2.4 GHz spectrum of wifi is made up of 11 different sub-channels, each spaced 5 MHz apart, and are each 20 Mhz wide. Boils down to channels 1, 6, and 11 being preferable. I'm no expert, but in my opinion you should implement an alternating channel scheme keeping maximum distance between repeated channel use to see if that helps. –  Nov 08 '13 at 00:56
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    The other obvious solution is to deploy 5GHz wifi, since those channels do not have the same overlap as 2.4. 5GHz does not travel through walls as well, but if there is an AP in each living unit, that shouldn't be too much of a problem. This obviously requires tenants to have 5Ghz capable hardware, which not everyone has. The way my university does this in its most congested buildings is to have both 2.4 and 5 http://images.macworld.com/images/howto/graphics/140685-spectrumbandoverlap_original.jpg –  Nov 08 '13 at 01:05
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    Wired by far beats wireless in reliability. I'd go with that baseline to avoid the "lack of promised utility" problem. People will tend to get their own equipment for wireless, but you could have shared access points local to clusters of apartments. They can be local thanks to the wired infrastructure, so no need for the wireless repeaters complexity. – apalopohapa Nov 08 '13 at 01:18
  • [This and the next part](http://blog.serverfault.com/2011/12/12/a-studied-approach-at-wifi-part-1/) are pretty good overviews on troubleshooting wifi. I've had good luck with inssider and a tablet (the PC version isn't as good) working out the best channel to use – Journeyman Geek Nov 08 '13 at 07:20
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    I personally don't like this question. There's much stress on the importance of fixing the issue (which is understandable) and the scale of the issue, but there's no information about the equipment used, there's no information about any type of band planning used, no diagrams of logical of physical connection between units, so there's very little that can be done at this point to help solve the issue other than some very general explenations. – AndrejaKo Nov 08 '13 at 07:28
  • Anyway, what I find very strange is the term `WAP-Repeater`. It's pretty ambiguous (but I could be wrong). It can mean a wireless range extender that just picks up existing signal, amplifies it and re-broadcasts it, but those work on the garbage in, garbage out principle and are in general very bad. The other option would be a more active device which actually does some processing on the signal, but still those are pretty bad as well, since they usually rely on transporting actual consumer data over WiFi, which takes up bandwidth. – AndrejaKo Nov 08 '13 at 07:33
  • What I've seen used the most in such setups and with most success is the use of sort of light weight access points that are connected together over wired Ethernet. They are then connected to a central controller from which the network can be administered. In the older systems, you'd place a hexagonal honeycomb-like structure over the floor-plan and then set a frequency and power for each cell, so that adjacent cells have different frequencies. Today, smarter systems can do that on their own. – AndrejaKo Nov 08 '13 at 07:38
  • This takes care of interference problems, since in such setups lightweight access points would be aware of eachothers's signal and using the control point can be adjusted to reduce their own transmit power so that the interference is minimized. If you have a large area which you yourself can administer, that can work well. If you can use 5 GHz, it can work even better due to larger number of channels and worse propagation on that band resulting in less interference. – AndrejaKo Nov 08 '13 at 07:40
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    @AndrejaKo I'm a software developer working primarily in a completely different division of the company (my division's multifamily product doesn't use this expensive distribution technology). I'm just now being made aware of this thing because of the issue with the 25% outage. When I have more information on the specs of the current installation I will definitely post them. And as a SE veteran, I also don't quite like this question, or better yet, my ignorance on the subject matter I'm trying to discuss. Thank you for your participation, and again I'll add more details as they become available – boulder_ruby Nov 08 '13 at 18:42
  • +1. Cheers, mate. Seems like you had a bad day yesterday :) – guitarthrower Feb 28 '14 at 17:24

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In short, yes, your bosses have probably been sold a bill of goods. I regularly get cold-called by people who would be happy to sell me a wireless network that costs 3 times as much as the fiber optic network I put in - which makes a dandy backhaul for low-cost, reliable WAPs that are connected by wires to fibers that connect between buildings.

There will be some interference, but with appropriate (low) power levels, it won't be that big of a deal if each Apt. has it's own, somewhat centrally located, router attached to a wire. You may hear other routers, but you'll hear your own router/access point best.

Business-model-wise, it probably makes more sense to provide wired internet (and let the customer field their own wireless) or just wires/fibers for the phone or cable or local internet companies to provide the actual service, unless your company actually has enough into this to provide a systems manager to keep it all running right; the cost of management and the hate and discontent that come from system problems are non-trivial, and will stick to your company if you set yourselves up in the role of internet provider (especially if you then fail to provide it reliably.)

However, there is no stubborn like the stubborn of a boss that has been sold a bill of goods and would lose face if he or she admitted that...and it's a very expensive stubborn.

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