wifi channel question

[mikeprice]

Hi all

 

We have just had a new wifi system put in - Unifi APs and controller on a server

 

Wonderful change - wifi access in all areas of the school at all time

 

I particularly like being able to use the management console to track the teachers and TAs as they move around the school - it's like Harry Potter!

 

 

However - I have a question

 

As far as I was aware - if 2 adjacent APs used the same channel number (2.4 not 5 ) then they would interfere and it would not really work

and in fact if the channels were too close this would always happen - in effect only channels 1 6 and 11 should be used

When I started here this was the main problem and I got the wifi system working (mostly) by sorting out the channels

 

However the new Unifi APs have all decided on their channels themselves and they have often chosen the same channel as a neighbour

BUT IT STILL WORKS

 

It looks like I am missing something - I am worried that if it stops working in a few years I will need to know

 

Any info would be wonderful

 

TIA

 

Mike

[DJ-1701]

Sounds correct to me. 1, 6 and 11 have always been the recommended channels in the UK as they have little to no interference with each other. Maybe they are outside the effected area? Strange.

[Mullaney18]

You don't need to set the channels, The Unifi controller manages the channels in par with its Zero hand off capability, which is like rolling all the access points into one and gives you the ability to roam around your site without negotiating with the neighbouring access points. It works as you say by putting all the the access points on the same channel and recognises its neighbour and if a device signal becomes stronger against another ap, then it will seamlessly switch.

 

One of my best purchases, although I've found if you do have too many aps close ( in like the same position but on different floors) hand off can fight each other, but if you plan it in well then it should never have a problem.

 

Although a word of warning, try stagger your ap upgrades, I've found said aps in our 2 storey building restart together, they can sometimes start on different Channels. But I might be wrong with that one.

 

Please anyone correct me if I was wrong.

 

Good link Here-

Edited April 24, 2016 by Mullaney18

[snagrat]

You don't need to set the channels, The Unifi controller manages the channels in par with its Zero hand off capability, which is like rolling all the access points into one and gives you the ability to roam around your site without negotiating with the neighbouring access points. It works as you say by putting all the the access points on the same channel and recognises its neighbour and if a device signal becomes stronger against another ap, then it will seamlessly switch.

 

One of my best purchases, although I've found if you do have too many aps close ( in like the same position but on different floors) hand off can fight each other, but if you plan it in well then it should never have a problem.

 

Although a word of warning, try stagger your ap upgrades, I've found said aps in our 2 storey building restart together, they can sometimes start on different Channels. But I might be wrong with that one.

 

Please anyone correct me if I was wrong.

 

Good link Here-

 

This isn't correct unless Unify have started to copy Meru.

 

Zero handoff does not need the APs to be on the same channel and really they should not be. Ideally 1,6,11 on the 2.4Ghz range

 

Only Meru (from the big players) do SCA (single channel architecture), everyone else does MCA (multi channel architecture).

[Mullaney18]

This isn't correct unless Unify have started to copy Meru.

 

Zero handoff does not need the APs to be on the same channel and really they should not be. Ideally 1,6,11 on the 2.4Ghz range

 

Only Meru (from the big players) do SCA (single channel architecture), everyone else does MCA (multi channel architecture).

 

I'm sure you read the link I provided from their help and support centre, if not, I'll quote the following on Zero Handoff

Zero Handoff Roaming works with any type of 802.11a/g/n client. However, all UAPs in the ZH-Enabled WLAN Group must be on the same layer-2 network (same subnet) and use the same wireless channel (e.g., Channel 1). Listed below are a few things to expect / avoid when deploying ZH-enabled UAPs.

Refer to linked article in previous post.

 

I have only heard of Ubiquiti and its Unifi range the last year or so but they are proving to match current technologies and popular, especially on EduGeek, as a better alternative to expensive equipment from the Big Players.

[mikeprice]

Thanks to all - I will trying restarting all the APs first thing tomorrow and see how they sort themselves out

[snagrat]

I'm sure you read the link I provided from their help and support centre, if not, I'll quote the following on Zero Handoff

Refer to linked article in previous post.

 

I have only heard of Ubiquiti and its Unifi range the last year or so but they are proving to match current technologies and popular, especially on EduGeek, as a better alternative to expensive equipment from the Big Players.

 

I did read the link but it does say this shouldn't be done in a large environment due to the error rate you will have.

[mikeprice]

Quick update - I have restarted all the APs and they have reset the channels - but in this area they are all on channel 6 again. I am assuming that this is due to the central controller/APs talking to each other to sort out the problems

 

Still all working anyway!

[mikeprice]

I did read the link but it does say this shouldn't be done in a large environment due to the error rate you will have.

 

I have read this article - but the problem is that it doesn't really define what a 'high density' environlemt is. I found a reference that seems to suggest that this would be something like a lecture theatre with everyone having a mobile and using a laptop

 

hence I am assuming (for now) that a class using 15 laptops wouldn't count