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Tricky thing to do

Last response: in Wireless Networking
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July 20, 2006 4:32:55 PM

Hello guys.

My name is Mihai, from Romania. I live in Bucharest, the country's capital. There's a massive paranoia here with the so called "neighborhood networks". Basically one guy with medium networking knowledge pays a mothly fee for a high speed fiber optic connection to a major ISP, ranging from 2mpbs to 50 mpbs clear channel then shares this internet connection across the neighborhood for prices that may vary from 10 to 15 USD and installation fees that range from 0 to 20-30 USD. They don't prioritize the traffic, they do this almost illegal, but most of the clients are very happy because of the low costs, the massive MAN bandwidth given to them by the peerings of these so called ISPs between them and between them and the major legit ISPs here in Bucharest.
Anyway... I was thinking to deploy such a network myself, but do this 100% legit, with guaranteed bandwidth for each one of my clients and the solution would have to be 802.11g.
I will give a few details about the location:
There are approx 5 buildings that are positioned like this:

  B1       B2
       B3
  B4       B5

I am living in B3. Every building has approx 320 apartments each, 160 on one side, 160 on the other side and 10 floors. They are build from massive concrete.

What would be the best way in your opinion to cover those 5 blocks with at least 10mbps sustained WiFi connections?
I am very familiar with the wireless networks, but so far I've deployed wireless networks in offices where there were 10-20 computers and I have absolutely no idea on how these setup will work (if it will work).
One option was to stuff these buildings with Linksys repeaters, another option was to place a Linksys WRT54GX router (True MIMO capable) on each side of B3, each one would be facing B1, B2, respectively B4 and B5.
B1 or B2 should have a WRT54GX facing B3 one one side and B4 or B5 should have one facing B3 on the other side. In the end we would have:
B3 providing signal to B1 and B2 with the SRX on one side and provide signal to B4 and B5 with the other SRX from the side facing them, B1 providing signal to B3 on one side and B5 providing signal to the other side of B3.
Perhaps it's more clear here: http://mach1.gotdns.com/scheme.jpg.

What I do not know is how will 4 SRXs handle the massive traffic that my customers will generate. They will most likely use filesharing software and we all know what that means.
I estimate approx 20-30 users in each building.
Also, the thing worth mentioning here is that is very unlikely that my customers will want to pay double for SRX ready wireless adapter, and will most likely have standard PCI/PCMCIA cards installed (not giving them the advantage of a true MIMO environment).

Please state your opinions here. I will appreciate every documented answer.

More about : tricky thing

July 24, 2006 10:38:23 PM

I can speak from experience and tell you that you absolutely do not want to even attempt something of this scale using Linksys hardware. It will just get crushed under the load, plus it doesn't hold up too well outdoors, where you will undoubtably be placing your APs.

To get any sort of reliable performance, you'll probably want to have some sort of wired backhaul for each building/floor. Most people don't realize the number of APs needed to fully cover an area this large. I used to be a wireless engineer and we did a lot of wireless install at hospitals where they wanted the entire place blanketed with wifi so they could access patient records, etc from anywhere. In a typical install we would place an AP roughly every 50-75 feet along corridors. Since your buildings are built from concrete you'll probably have to space them even closer because we were just dealing with drywall.

I'm assuming you have some sort of permission from the building management for this project, because it's suicide to even attempt it if you don't. If you still wanted to try, I'd find a central location in each building to wire your APs back to, then I'd run fiber from each building back to the demarcation point where the Internet connection comes in.

And as far as "guaranteeing" bandwidth for every customer, this is all but impossible. It's hard when you have full control over the customer's computer and what type of wireless card they have and virtually undoable otherwise, as in your situation.

Another problem you're going to run into is RF interference. This is why we always placed APs so close together, so if someone decides to fire up the microwave for 10 minutes, his neighbor doesn't get kicked offline. Channel planning is always a challenge too. Airespace makes really good stuff and their APs can "self regulate" their transmit power to avoid interference with nearby APs. Plus, in your environment you can't do anything to prevent rogue APs that people decide to set up in their apartements. These will wreak havoc with the best planned wireless network.

I don't mean to come across negative, but a project of this scope is just probably way out of your budget, time and manpower scope.
July 27, 2006 12:45:25 PM

If all the buildings are made of massive concrete, I don't think that you will be able to setup a WiFi network.

If I were you, i would have used cables instead of wireless connections.
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July 27, 2006 1:01:26 PM

Cabling after the fact is usually difficult because the only "easy" way to do it is to run your cabling along exterior walls on the outside of the building and then just drill through to the inside of the apartments. Apartments rarely have drop ceilings or attic space, so it's unlikely you can bring a cable in from the inside of the building.
July 27, 2006 10:53:05 PM

Well, some of my friends have their Internet-cables hanging out of the windows and into another room, because their cables aren't long enough to get from their Router's to all of the PC's in the houses. :p 


And both of them are using Belkin Routers, which I've heard isn't the best and therefore they are using cables instead of WiFi connections.
July 28, 2006 12:40:34 AM

Quote:
Well, some of my friends have their Internet-cables hanging out of the windows and into another room, because their cables aren't long enough to get from their Router's to all of the PC's in the houses. :p 


And both of them are using Belkin Routers, which I've heard isn't the best and therefore they are using cables instead of WiFi connections.


You could never get away with anything so sloppy on a professional job. Plus, regular cat5 will only hold up outdoors for so long before the sun starts to eat away the jacket or moisture gets inside. At the bare minimum I'd do outdoor cat5, secured to the building with cable clamps every 5-6 feet and use a coax style cable shield with a fair amount of silicone where it enters the building. And that would be the last resort, I really hate having visible cable because it detracts from the quality of the whole job. But then again, I wired my whole house with about 15 drops and had two full size racks in a closet so you could say I take things to extremes.
August 2, 2006 6:56:17 PM

Out of the scope of your abilities I'm afraid. Message boards are pretty good for Joe Average to ask questions about getting dropped connections, how to setup a bridge to extend the WLAN in their house, ie...very basic questions.

Truth is nobody can give you any solid advice about how to do it because on mid to large jobs (this would qualify as a mid size job) there is no guessing. It's all done with detailed site surveys.

If you really want to undertake this then I suggest you engage a company, or perhaps a person you know, that is capable of making it happen. Simply by coming here and asking these questions you've virtually disqualified yourself from that perspective.


Note: Fred, you were never a wireless engineer. You were a tech. A grunt. That's all you ever could have been based on some of the responses I've seen from you. It's cool you have this inflated opinion of yourself. Confidence is a good thing to a point but you should be careful making claims like that. You never know who might be listening, or in this case, reading. Don't take it personally. I've read your posts and your little vanity webpage. Your a tech. It's cool.
August 3, 2006 2:19:56 AM

Quote:
Note: Fred, you were never a wireless engineer. You were a tech. A grunt. That's all you ever could have been based on some of the responses I've seen from you. It's cool you have this inflated opinion of yourself. Confidence is a good thing to a point but you should be careful making claims like that. You never know who might be listening, or in this case, reading. Don't take it personally. I've read your posts and your little vanity webpage. Your a tech. It's cool.


If that's your opinion then you're certainly entitled to it. :D  My current position while going to school full time is network tech, previously I worked for two ISPs and a WISP, so I thought I would share some of the experience I have that directly relates to this thread and - because, well, I thought that was the point!

I'm not sure why you decided to single me out, because there are tons of other people on the board that post *extremely* incorrect information. If you feel responses I posted here contained incorrect information, I would be interested to see which ones in particular you were referring to.
!