Wifi advice - Tilted Forum Project Discussion Community

TheProf · 06-12-2011, 08:22 PM

Hello everyone,

I hope you are all well.

I'm setting up the technology in a new building and one of the requirements is to have different wifi coverage in the same building. The building houses 3 different organizations all adjacent to each other so I'm not sure the best way to proceed.

Imagine a 2 story building with a hallway on each floor and office rooms on both sides. Floor 1 left side and floor 2 left side is all organization A. Floor 1 right side is organization B, Floor 2 right side is organization C. Hope that is clear

So each organization wants their own WIFI signal. I am able, through the wireless router computer (pfSense) to have 3 different subnets coming out of it and prevent anyone on one wireless network from accessing the others. So from the isolating each group that's no problem.

The question comes to what is the best approach from the actually wireless access points. Do I put individual access points for organizations A, B, and C? Will the fields overlap and will that cause interference or problems? or is there an access point that can generate all 3 independent fields (or just 2 for example) and then it will sort them all out? Any recommended hardware?

Looking for your guidance!

Thanks!

Hotmnkyluv · 06-12-2011, 08:36 PM

I am no engineer but I don't think overlapping areas of coverage will affect one another.
Where I live I can search for wi-fi signals and other than my own router, I pick up 1 business and 3 of my neighbors.
(if it matters to the discussion or if you're curious, one of them is unlocked, has been told, knows, and doesn't care)
I game. I watch movies. I surf the web on 3 different computers. I ipad constantly. I watch live TV. I stream music / radio. Often several of these things at the same time.
I imagine all my neighbors are doing the same... No problems.

Martian · 06-13-2011, 06:25 AM

This will depend partly on the size and layout of the building, but you'll want a minimum of three access points -- one for each organization. Set the APs to channels 1, 6 and 11 so that each has it's own and interference won't be an issue. If coverage for the folks spanning two floors is insufficient, you can add a fourth AP set to the same channel as the client on the first floor, opposite side.

Having access points in range of each other on the same channel can lead to collisions and interference, and can result in dramatic drops in range and/or throughput.

Jove · 06-13-2011, 06:44 AM

I agree with Martian and Hotmnkyluv and would like to add that you might want a different SSID for each floor or department.

TheProf · 06-13-2011, 01:01 PM

Hello everyone,

So to summarize the points made so far to make sure I understand:
1) Different SSIDs for each organization
2) Different transmission channels from the AP
3) Spread out the APs

Any particular hardware to look for or to avoid? Also is there a way to control the wifi range to limit it somehow to only one floor? Different antenna perhaps?

Thank you

crazybobmarley · 06-13-2011, 02:52 PM

Quote:

Originally Posted by TheProf

Any particular hardware to look for or to avoid? Also is there a way to control the wifi range to limit it somehow to only one floor? Different antenna perhaps?

No. I like Linksys or Cisco, although I'm not a fan of their newer routers/aps without the antennas. I've had good luck with TP Link as well.

No, but again you don't need to, simply place them on seperate channels like suggested above. You can turn off the SSID broadcast so that way noone can connect to the other networks unless they know the name, but I imagine you're going to implement some kind of security which essentially does the same job, this is just more thorough.

A different antenna would only increase range.

Martian · 06-13-2011, 03:21 PM

Each network should have it's own SSID and encryption key. If more than one AP are on the same network and you want to allow your users to roam, you can use the same SSID and key but different channels. Ie, router one broadcasts an SSID of "network A" on channel 6 and uses an encryption key of "key1" (note: do not actually use this as it's terrible). Router two also broadcasts an SSID of "network A" and uses the key of "key1" but broadcasts on channel 11. This will allow your users to move smoothly from one AP to the other. Keep in mind that in a setup where you have more than one AP on the same network, you'll need to ensure you only have one DHCP server. You can use one AP or the other, or you can use a separate router for the job.

You can disable SSID broadcast if you want to, but be advised that this won't stop any but the most casual/clueless of intruders. You can also enable MAC filtering, which will put up a similar roadblock. Neither of these are fool-proof -- the only sure way to secure your network is to use a proper encryption scheme with a strong authentication mechanism. WPA-PSK using AES with a long (16+ character) random key is the best choice.

Third party firmware for some routers will allow you to adjust the signal strength of your AP by tweaking the output power, but it's not usually worth it. As long as they're on separate channels they won't interfere with each other.

I have a strong preference for Linksys gear. In terms of consumer-grade equipment there isn't much better.

I think that about covers it.

TheProf · 06-13-2011, 05:04 PM

This is great information -- thank you!

I certainly will look into the Linksys.

I came across this item by EnGenius -- pretty cool in that it is very unobtrusive and seems to have a lot of capabilities.

Newegg.com - EnGenius EAP9550 802.11 b/g/n Wireless Access Point/Repeater

I didn't see any specific issue with it but thought to ask for input also.

Thank you.

06-12-2011, 08:22 PM	#1 (permalink)
TheProf Crazy	Wifi advice Hello everyone, I hope you are all well. I'm setting up the technology in a new building and one of the requirements is to have different wifi coverage in the same building. The building houses 3 different organizations all adjacent to each other so I'm not sure the best way to proceed. Imagine a 2 story building with a hallway on each floor and office rooms on both sides. Floor 1 left side and floor 2 left side is all organization A. Floor 1 right side is organization B, Floor 2 right side is organization C. Hope that is clear So each organization wants their own WIFI signal. I am able, through the wireless router computer (pfSense) to have 3 different subnets coming out of it and prevent anyone on one wireless network from accessing the others. So from the isolating each group that's no problem. The question comes to what is the best approach from the actually wireless access points. Do I put individual access points for organizations A, B, and C? Will the fields overlap and will that cause interference or problems? or is there an access point that can generate all 3 independent fields (or just 2 for example) and then it will sort them all out? Any recommended hardware? Looking for your guidance! Thanks!

06-13-2011, 06:25 AM	#3 (permalink)
Martian Young Crumudgeon Location: Canada	This will depend partly on the size and layout of the building, but you'll want a minimum of three access points -- one for each organization. Set the APs to channels 1, 6 and 11 so that each has it's own and interference won't be an issue. If coverage for the folks spanning two floors is insufficient, you can add a fourth AP set to the same channel as the client on the first floor, opposite side. Having access points in range of each other on the same channel can lead to collisions and interference, and can result in dramatic drops in range and/or throughput. __________________ I wake up in the morning more tired than before I slept I get through cryin' and I'm sadder than before I wept I get through thinkin' now, and the thoughts have left my head I get through speakin' and I can't remember, not a word that I said - Ben Harper, Show Me A Little Shame

06-13-2011, 03:21 PM	#7 (permalink)
Martian Young Crumudgeon Location: Canada	Each network should have it's own SSID and encryption key. If more than one AP are on the same network and you want to allow your users to roam, you can use the same SSID and key but different channels. Ie, router one broadcasts an SSID of "network A" on channel 6 and uses an encryption key of "key1" (note: do not actually use this as it's terrible). Router two also broadcasts an SSID of "network A" and uses the key of "key1" but broadcasts on channel 11. This will allow your users to move smoothly from one AP to the other. Keep in mind that in a setup where you have more than one AP on the same network, you'll need to ensure you only have one DHCP server. You can use one AP or the other, or you can use a separate router for the job. You can disable SSID broadcast if you want to, but be advised that this won't stop any but the most casual/clueless of intruders. You can also enable MAC filtering, which will put up a similar roadblock. Neither of these are fool-proof -- the only sure way to secure your network is to use a proper encryption scheme with a strong authentication mechanism. WPA-PSK using AES with a long (16+ character) random key is the best choice. Third party firmware for some routers will allow you to adjust the signal strength of your AP by tweaking the output power, but it's not usually worth it. As long as they're on separate channels they won't interfere with each other. I have a strong preference for Linksys gear. In terms of consumer-grade equipment there isn't much better. I think that about covers it. __________________ I wake up in the morning more tired than before I slept I get through cryin' and I'm sadder than before I wept I get through thinkin' now, and the thoughts have left my head I get through speakin' and I can't remember, not a word that I said - Ben Harper, Show Me A Little Shame

06-12-2011, 08:36 PM	#2 (permalink)
Hotmnkyluv Tilted Location: Sunny South Florida	I am no engineer but I don't think overlapping areas of coverage will affect one another. Where I live I can search for wi-fi signals and other than my own router, I pick up 1 business and 3 of my neighbors. (if it matters to the discussion or if you're curious, one of them is unlocked, has been told, knows, and doesn't care) I game. I watch movies. I surf the web on 3 different computers. I ipad constantly. I watch live TV. I stream music / radio. Often several of these things at the same time. I imagine all my neighbors are doing the same... No problems.

06-13-2011, 06:44 AM	#4 (permalink)
Jove Groovy Hipster Nerd Location: Michigan	I agree with Martian and Hotmnkyluv and would like to add that you might want a different SSID for each floor or department.

06-13-2011, 01:01 PM	#5 (permalink)
TheProf Crazy	Hello everyone, So to summarize the points made so far to make sure I understand: 1) Different SSIDs for each organization 2) Different transmission channels from the AP 3) Spread out the APs Any particular hardware to look for or to avoid? Also is there a way to control the wifi range to limit it somehow to only one floor? Different antenna perhaps? Thank you

06-13-2011, 05:04 PM	#8 (permalink)
TheProf Crazy	This is great information -- thank you! I certainly will look into the Linksys. I came across this item by EnGenius -- pretty cool in that it is very unobtrusive and seems to have a lot of capabilities. Newegg.com - EnGenius EAP9550 802.11 b/g/n Wireless Access Point/Repeater I didn't see any specific issue with it but thought to ask for input also. Thank you.