What Channel?

[TechSupp]

We are right next to a housing estate and our wifi gets crowded on certain channels 1,6 and 11 which happens to be the ones our AP's are set to. The other week I changed the channel of one AP away from a crowded one (due to terrible performance) which resulted in much better performance of our AP. Now found out another AP along the school is now on the same channel as a lot of the close by routers. Can I use the other channels in between and if so how many channels should I leave between adjacent AP's.

[Arthur]

It might be worth getting a new 'n' or 'ac' wireless router so you aren't limited to the 2.4GHz frequencies which all overlap each other.

 

http:// http://en.wikipedia.org/wiki/List_of_WLAN_channels

 

http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/2.4_GHz_Wi-Fi_channels_%28802.11b%2Cg_WLAN%29.svg/1440px-2.4_GHz_Wi-Fi_channels_%28802.11b%2Cg_WLAN%29.svg.png

Edited November 12, 2014 by Arthur

[TechSupp]

New APs are not an option and the current ones are Ruckus and are dual band, problem is all our devices are 2.4 and also not likely to be changed.

[TechSupp]

Yes it should do, but when we first had it, it caused issues so it was set up with fixed ones.

[avenn]

Hi techsupp,

 

 

They are 11 chans avail in uk but these are from the days of 5 MHz channels not the nowadays 802.11 20/40/80 channel widths. The wider the channel the more data = faster data rate.

 

 

5mhz channels at the time were not going to give us the speeds needed.

 

 

In the uk we can only use the range 2.4 to 2.4835 see ofcom doc: http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-information/UKFAT_2013.pdf

See diagram.

 

 

We use 1 6 11 as a BEST PRACTICE in that it maximises 20mhz chan usage without interference. It’s about not overlapping your actual channels otherwise interference. So in reality we have 3 possible 20mhz channels and only 1 x 40mhz channel.

Channels 5 and 10 are "spacers" between 1 6 and 11 to avoid interference. On a frequency analyser channels don`t just drop of neatly at the end - they are like a steep slope - see diagram - middle and bottom graph.

 

 

So when you say can I use the other channels - it depends (again) - as long as nothing else is using that range. But in my experience this is highly un-likely due to 2.4ghz freq range now considered a saturated / screwed up range.

 

 

So what can you do?

 

 

1. Well auto freq is not much use as it changes at that point in time only / other APs on a separate autonomous system within range can do the same and it can be a merry go round causing end device probs etc – there is also not much it can jump to (2.4) as its all taken.

2. You could speak to the problem device owners – they may also/likely have wireless issues (your system interferes with there systems) – i`ve knocked on doors in the past and offered to fix for free and put there ap on a fixed non- interfering channel (you will need to channel plan) and lowered the power so it doesn’t slip through to your location. 2.4ghz is a slippy frequency which is one of its main issues when lots of Aps. Power control is v important in crowded enviro. A little initial hassle but might sort both people’s issues. Win Win?

3. Invest in 5GHz end user kit. If you want it to work u might have no choice? But with 80mhz chans on the way this may/will become crowded. Then we will need 60ghz – coming soon / 802.11ad!

4. Send email to Ofcom – tell them politely to get arse in gear – more freq please and limit channel size! They are reviewing freq allocation at mo: Ofcom | About this document

 

 

They need to give it to the free market (which makes excellent tax dollars) not auction to the richest git!

 

 

By the way I use mikrotik which allows me to use 5mhz channels. Very tailor able!

 

 

Hope the above helps and good luck!

 

 

Aidan Venn MSc, MTCNA, CCNA blah blah blah……..

[TechSupp]

Well, thanks for the detaile reply and better understanding now and from reading further looks like sticking with 1, 6 & 11 is the way to go. From your suggestiins,

1, tried and reason we now have fixed channels

2, not going to happen due to time, and comeback if anything happens however unrelated!

3, too much existing kit on 2.4 to just dunp it

4, more sucess spitting into the wind!

 

Does not leave me many options does it 😭 thanks for the info anyway.

Edited November 16, 2014 by TechSupp