Hello, i have a question about channel witdh
What means:
Ceee
eCee
eeCe
eeeC
Ce
eC
‘C’ is your control or main frequency, and ‘e’ is your extension channel or channels.
This is the new way of representing the previously used -above-control and -below-control
Hello Cybertod, thanks for the quick reply.
Can you explain more specific in details please
How can i use two channels
How can i use one channel
Decide what channel width you want to use depending on the throughput requirement and available spectrum - 20,40 or 80Mhz
If you choose 20/40/80 it will try to use 80Mhz. But in my observation when doing spectral scan the ‘C’ frequency is the one that is used the most.
Example:
Ceee if 5400 is selected freq this means 5400+5420+5440+5460 for 80mhz will all be used. If using a smaller channel size, there’re less “e”'s or extension channels.
Example, 40 MHz bandwidth with Ceee and 5400 selected means 5400+5420 will be used. e to the right of C earns above and e to the left of C means below.
Clear now?
Yes this is clear now thanks.
I am not sure if eCee / eCeee or eCee / eeeCe is really possible?
Can anybody confirm it is? I don’t have ac units to actually test.
I had the understanding that only Ce / Ceee & eC / eeeeC etc was possible. Thus extension channels only ‘under’ or ‘above’ the center channel. But I might be mistaken?
And in relation to this;
Would a station with eCee now follow an AP that actually has set Ceee? Or eeeC? (As long as the bandwidth is the same it follows?)
In the future when we see 160Mhz wide channels, would a station has to be set to eeeCee for instance to make it to follow ANY setting of a 7x20=140Mhz wide operating AP?
It follows ap. I’ve set my station to custom channels and all of them are Ceee. Then I try eeeC on ap and the station connects at full rate.
hmm ya, but what if AP is set to eCee (it that is possible, still nobody replied to this question) and CPE to Ceee or eeeC, or eeCe, would it still follow?
And if AP is set to eCee and CPE to Ce only. Which channels will now actually be used? eC or Ce? (Does now CPE suddenly HAS some right of decision…?)
As I understand the AP does the decision. So the “eCee” setting is only meaningful at the AP.
The CPE/station ignores this setting and follows. I’m not sure if every cpe has to follow on all
channels. So with Ceee at the AP some stations might do C, Ce or Ceee?
I haven’t tried all those combinations, but the C channel being the control channel is the one that is important.
And if the station has the same C channel in the scan-list it will be able to connect. After that, and I say that without being sure just how I think it is - the type of extension Ceee, eeeC, eCee is transmitted with some management frames and the station is able to adjust.
Doing a wireless scan you see the SSID and a channel like this: 5180/20-Ceee/ac(13dbm).
So the AP sends the channel plan with the beacon.
Yes, you are correct - Station will use the settings that AP provides regardless what it has on the client side for channel width unless on the client side you have smaller supported channel width that on the AP.
How does the algorithmus work for scaling down due to interference/bad CCQ?
Does it go down with modulation on a 80MHz Channel and then reduce the Channel size or is there
a list of Channelsize/Modulation rate combinations which it steps up/down.
I would like to overlap extension channels of APs on the same tower and use/release them on demand.
So if the APs would first reduce channel size when they interfere they can keep a higher modulation on
the remaining smaller channels.
Good day,
I need your assistant on I link I established across a lagoon over a
distance of 29km, having a signal strength of 64db, link works fine at
morning but once it’s noon signal strength increases up to 75-81db which
makes the link disconnect and unusable. Am using Mikrotik Netmetal and a 34dbi parabolic dish antenna. Please
advice on what to do to eliminate this. and also Am using a channel width of 20/40/80Mhz Ceee
Thank you.
ok Guys so in this example:
eCee with 5400 means;
e C e e
5380 5400 5420 5440
???
Yes indeed
“C” is a central frequency?
So 5400 means range 5390-5410
and then
5400 eCee spectrum range should be
5370-5450
All Frequency setting are central.
C = control channel
Yes, and its 20Mhz wide. Every “e” means another 20Mhz wide channel that is attached to the first, ‘center’ frequency.
Any client that connects to this AP should at least be able to ‘talk’ on the center frequency.
ac protocol now actually is smart enough to ‘sense’ if one of the other ‘e’ channels has interference and skips this channel for immediate usage. It still communicates with cpe on the other ‘c’ and ‘e’ channels, but with less speed than the theoretical max. off course.
So, if AP works 5600 eCee (=80Mhz) it can connect to station that is set to 5600 ‘C’ or 5600 ‘eCe’ or ‘eCee’ and probably (?) even on ‘Ce’. (This is a presumption from my end. Don’t know for sure and since no ac radios yet, can’t test it.)
Also;
If AP works on 5600 eCee representing 5570-5590+5590-5610+5610-5630+5630-5650 and station works on same, but the protocol ‘senses’ (its described on the internet somewhere, can’t remember where 
) that for instance on 5610-5630 the signal is disturbed (I believe AP ‘tests’ each channel to get a sort of CCQ value, if its poor it omits using that channel for data transport) it won’t use that channel. But the other 3 available channels are still used for data. Maximum throughput is now obviously lowered to a level that belongs a 3 channel wide bandwidth.
The nice thing is now that interference is often a variable event, and traffic demand is also often variable.
You can now setup a 80Mhz wide backhaul link in an area that has many other wifi usages. At times it CAN handle its full potential (when all channels are ‘clean’) but when due atmospheric circumstances or whatever suddenly one of the underlying 20Mhz channels gets hammered, the backhaul still delivers a high quality link, only a bit lower in maximum throughput.
If you compare this to a normal ‘n’ or ‘a’ channel set backhaul link which become very unstable and unreliable in case of interferences, this ‘ac’ channel setup has a bit of what I would call “interference avoidance technology”.
[On ‘n’ based backhaul you have to pick a 40Mhz wide channel you hope is free. You might get for instance 150Mb real data throughput if the spectrum stays free. If you now need to guarantee 150Mb data you can opt to use an ‘ac’ backhaul. Set it to 80Mhz and pick some centre channel that seems to be relatively free. Run it and under the same ‘clean spectrum’ circumstances as with the ‘n’ link you’ll get even higher throughputs (up to 800Mb). BUT, more important, you can sleep in peace, because even some disturbing radio waves that will molest part of your channels is not going to ruin your link. Actually you can ‘lose’ 2 out of the 4 channels to still be able to deliver 150Mb real data! You backhaul suddenly became much more reliable than one based on ‘n’. At a fraction more expenses than the ‘n’ link. Ain’t that marvellous!
Off course, when you’re continuously seeking the maximum in a 80Mhz (or 120Mhz!) wide channel you’d better move your link to the Sahara desert, or the moon 
If such high throughput (1.8Gb!) is required, you might think of other solutions.
IN an indoor environment where both AP and stations all support ac and have good signal (256 QAM 5/6 !) and you have no close range other wifi signals you might see it happen!
You can then swap your pirate-bay files (!) from one device to another in minutes of time…well… lucky you. 