Community discussions

 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Why channel 50 isn't selectable in the 160Mhz band?

Mon Jul 01, 2019 9:05 pm

Greetings,

I have a couple of RB4011iGS+5HacQ2HnD-IN devices and for quite some time now I was wondering the following:
Why is it that we can only select frequencies in the 5500-5560 range when the 5GHz WiFi is set to operate in the 160MHz band?

According to the list of WLAN channels found here, this restricts our available options to just channel 114, which is largely considered DFS in Europe.
Channel 50 on the other hand may have some DFS in it too, but in Europe it's designated for Indoors usage as well.
However, it's frequencies (5170-5330MHz) are not available for selection at all.

Should a weather radar be detected on the frequencies that channel 114 occupies, that results in 30 minutes without 5GHz WiFi, since it has to immediately evacuate due to DFS.
If you don't have the option to select the alternative 160MHz channel, in hopes of avoiding that radar, then what is the point of even offering 160MHz functionality in the first place? Just to hope that you'll be fortunate enough to reside adequately far from it?

I posed that question to support in January, but it remains unanswered since.
 
pe1chl
Forum Guru
Forum Guru
Posts: 5832
Joined: Mon Jun 08, 2015 12:09 pm

Re: Why channel 50 isn't selectable in the 160Mhz band?

Mon Jul 01, 2019 9:35 pm

For what country?
It can be that in your country there is no 160 MHz wide span in the low channel numbers.
Remember the channels are only 20 MHz wide so you need 8 adjacent channels starting from the channel you set (assuming Ceeeeeee layout).
In case of Ceeeeeee layout the channel should be 36 instead of 50.
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Mon Jul 01, 2019 10:00 pm

Just went ahead and checked every single country option. The sole difference is that some countries are offered an additional channel (5580MHz on "Ceeeeeee").
As it currently stands, nobody has the ability to select channel 50. The only option which will allow frequencies from 5120 to 5560 is the debug one (which I'm not sure if it even works).
Last edited by Frostbyte on Tue Jul 02, 2019 11:12 am, edited 1 time in total.
 
pe1chl
Forum Guru
Forum Guru
Posts: 5832
Joined: Mon Jun 08, 2015 12:09 pm

Re: Why channel 50 isn't selectable in the 160Mhz band?

Mon Jul 01, 2019 11:04 pm

What is your channel layout?
This is set via the channel-width parameter e.g. 20/40/80/160mhz-Ceeeeeee
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 9:34 am

Usually "Ceeeeeee" or "XXXXXXXX", however shifting the layout further only serves to increase the frequency range (with a maximum possible at 5640-5700).
 
pe1chl
Forum Guru
Forum Guru
Posts: 5832
Joined: Mon Jun 08, 2015 12:09 pm

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 11:13 am

When you have Ceeeeeee you should not be using channel 50 but rather use channel 36. The C indicates the position of the control channel which is the lowest channel in this case, the e are the extension channels, all 7 are above the control channel in this case. There are no 7 available channels above 50.

Note that this 160 MHz bandwidth mode is mainly there for the sales brochures. To boast the highest possible (theoretical) transfer speed.
In practice it is usually better to set a lower bandwidth so you have better signal/noise ratio and less problems with interference.
Personally I would not go above 80 MHz and the system I operate at work even uses only 40 MHz bandwidth.
The indicated "wifi speed" then is up to 400 Mbit/s.
(of course, unlike with wired ethernet, this does not mean it can transfer 400 Mbit/s, these figures are hogwash and as a first approximation for realistic transfer speed you need to halve them)
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 12:02 pm

When you have Ceeeeeee you should not be using channel 50 but rather use channel 36. The C indicates the position of the control channel which is the lowest channel in this case, the e are the extension channels, all 7 are above the control channel in this case. There are no 7 available channels above 50.
Image

Channel 36 is a 20MHz-wide one, when referring to the 160-wide band the only options are either 50 or 114, as they are basically a group of all the smaller ones.
Regardless, I could just as well choose to position the control channel in the middle. There is no reason to argue over semantics.
What is even the point of discussing layouts, when every possible option doesn't allow you to go even remotely near the frequencies that channel 50 spans across?

Note that this 160 MHz bandwidth mode is mainly there for the sales brochures. To boast the highest possible (theoretical) transfer speed.
In practice it is usually better to set a lower bandwidth so you have better signal/noise ratio and less problems with interference.
Personally I would not go above 80 MHz and the system I operate at work even uses only 40 MHz bandwidth.
The indicated "wifi speed" then is up to 400 Mbit/s.
(of course, unlike with wired ethernet, this does not mean it can transfer 400 Mbit/s, these figures are hogwash and as a first approximation for realistic transfer speed you need to halve them)
Yes, there are still very few devices that can take advantage of 4x4 MIMO and 160MHz-wide channels.
Yes, I still prefer to use the cable whenever possible. Yes, the 80MHz-wide option is the one I'm currently using myself as well.
No, I do not have delusions about the speed (advertised or actual) of the medium, I have done my experiments and research long before coming here to create this thread.
But, brochure or not, they are providing this as a feature of the device. I should as well be able to experiment with the darn thing, even if I don't ultimately stick with it.
I do not appreciate when I'm given a feature, but only half of the options that go along with it. If it's not implemented proper, then it's false advertising.

PS: Excuse my irritated tone, but I really can't stand when folks are defending marketing bs.
Last edited by Frostbyte on Tue Jul 02, 2019 1:32 pm, edited 1 time in total.
 
muetzekoeln
Member Candidate
Member Candidate
Posts: 142
Joined: Fri Jun 29, 2018 2:34 pm

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 12:45 pm

This is only about naming conventions!

https://support.metageek.com/hc/en-us/a ... c-Channels

Mikrotik does not use the AC channel naming but gives you control where your 20MHz control channel is positioned.

E.g.: AC 160Mhz "channel" 50 can be set on Mikrotik by specifying
channel 36 and "Ceeeeeee"
or
channel 40 and "eCeeeeee"
or
...
channel 64 and "eeeeeeeC"
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 1:12 pm

Mikrotik does not use the AC channel naming but gives you control where your 20MHz control channel is positioned.

E.g.: AC 160Mhz "channel" 50 can be set on Mikrotik by specifying
channel 36 and "Ceeeeeee"
or
channel 40 and "eCeeeeee"
or
...
channel 64 and "eeeeeeeC"

You all appear to be mistaking that I'm not aware of how the control channel selection works. I already know this.

What I don't get is where you're seeing channels 36, 40, 64 and so forth, when configuring for 160MHz.

When 160MHz is selected there are no options to choose any frequency from the 5170-5330MHz range (where said control channels would normally reside in).
You're free to provide with a working example of course, if you find it, that is.
 
pe1chl
Forum Guru
Forum Guru
Posts: 5832
Joined: Mon Jun 08, 2015 12:09 pm

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 2:40 pm

Sorry I personally do not have any MikroTik device that can do 160 MHz channels so I extrapolated what I wrote from what I see with smaller bandwidths and the channel layout.
What @muetzekoeln wrote is correct and is different from what you depict, some people are confused by that.

I do have other 160 MHz equipment (from UBNT), it too shows fewer channel options the wider you set the radio, but it allows channel 36 with 160 MHz bandwidth.
(in that firmware there also are channel numbering inconsistencies, even internally in the firmware, what shows up as 36 here may show as 38 somewhere else)

I agree that most of WiFi is about marketing bs. But as everybody does that, it is difficult for a single manufacturer to break through that as they would rate negatively in naive comparisons.
 
Reinis
MikroTik Support
MikroTik Support
Posts: 57
Joined: Wed Jan 02, 2019 12:14 pm
Location: Latvia
Contact:

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 2:42 pm

What I don't get is where you're seeing channels 36, 40, 64 and so forth, when configuring for 160MHz.
In RouterOS, you don't specify the channel, but rather the frequency. So for example, to get channel 36, you set Frequency 5180 (channel-width=20/40/80/160mhz-Ceeeeeee)

When 160MHz is selected there are no options to choose any frequency from the 5170-5330MHz range (where said control channels would normally reside in).
Frequency list is restricted by the configuration of country and Frequency Mode.
The limit can be lifted by using country=no_country_set and frequency-mode=superchannel
This is not recommended. Contact your local authority to know which frequences can be used legally

You're free to provide with a working example of course, if you find it, that is.
Sadly, it's not that simple. 160MHz support is implemented in various ways by the manufacturers.
For example, to achieve 160MHz connection with RB4011-WIFI and Intel-9260 AC card, you have to disable four chains (2x Tx and 2x Rx).
For the particular wireless chip, it's most likely due to that it does not support 80+80MHz thus it does not know about extended NSS flag

An example:
set [ find default-name=wlan1 ] band=5ghz-onlyac channel-width=20/40/80/160mhz-Ceeeeeee disabled=no frequency-mode=superchannel mac-address=\
 B8:69:F4:AD:C8:FA mode=ap-bridge name=5GHz radio-name=B869F4ADC8FA rx-chains=0,2 security-profile=password ssid=TEST160 tx-chains=0,2 \
 wmm-support=enabled
Note, that this is pretty useless as the actual speed does not change between 1S-160MHz and 2S-80MHz (2S-160MHz vs 4S-80MHz and so on)

Using RB4011-WIFI <==> RB4011-WIFI requires no tweaks in order to use all chains with 160MHz.
As mentioned, it is highly dependant on the host device chip manufacturer and how they have implemented the usage of NSS and NSS Extended Flags (driver level).
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 02, 2019 4:32 pm

In RouterOS, you don't specify the channel, but rather the frequency. So for example, to get channel 36, you set Frequency 5180 (channel-width=20/40/80/160mhz-Ceeeeeee)
There appears to be some confusion still. Let me clarify once more that I know that in RouterOS we don't set them via the numerical/traditional way.
I know how to match the channels to frequencies, because that information is readily available. I am only referring to them via numerals because it's easier to convey.
When I was replying by "where do you see channels 36, 40, 64 and so forth" what I meant was "where do you see the frequencies corresponding to those channels, because they are not offered". I am not expecting to see channel numbers, I am expecting to see their corresponding frequencies.. and the problem is that half of my options are missing here.

Frequency list is restricted by the configuration of country and Frequency Mode.
The limit can be lifted by using country=no_country_set and frequency-mode=superchannel
This is not recommended. Contact your local authority to know which frequences can be used legally
I am aware of superchannel, however none of my wireless devices are able to even discover the SSID when this option is selected. (Even in 80MHz-wide mode where regulatory-domain normally works)
I am not sure of the "debug" country option however. Assuming it doesn't suddenly vanish in the future, being called debug and all.

But, if we are to return to the original question of this thread..
Why is it that the 5170-5330MHz frequencies which exist in the 802.11ac spec and selectable on devices from other vendors, not being offered under any country option in MikroTik devices? (When used in 160MHz mode)
^ This is what I want you to primarily answer me, instead of eluding to a blanket statement called "restrictions".
Other vendors certainly doesn't seem to have those "restrictions", as pe1chl mentioned (being able to select the 160MHz-wide channel within the 5170-5330MHz range on his UBNT device).

Sadly, it's not that simple. 160MHz support is implemented in various ways by the manufacturers.
For example, to achieve 160MHz connection with RB4011-WIFI and Intel-9260 AC card, you have to disable four chains (2x Tx and 2x Rx).
For the particular wireless chip, it's most likely due to that it does not support 80+80MHz thus it does not know about extended NSS flag

An example:
set [ find default-name=wlan1 ] band=5ghz-onlyac channel-width=20/40/80/160mhz-Ceeeeeee disabled=no frequency-mode=superchannel mac-address=\
 B8:69:F4:AD:C8:FA mode=ap-bridge name=5GHz radio-name=B869F4ADC8FA rx-chains=0,2 security-profile=password ssid=TEST160 tx-chains=0,2 \
 wmm-support=enabled
Note, that this is pretty useless as the actual speed does not change between 1S-160MHz and 2S-80MHz (2S-160MHz vs 4S-80MHz and so on)

Using RB4011-WIFI <==> RB4011-WIFI requires no tweaks in order to use all chains with 160MHz.
As mentioned, it is highly dependant on the host device chip manufacturer and how they have implemented the usage of NSS and NSS Extended Flags (driver level).
Thank you for taking the time to do this write-up; much appreciated.

Just to clarify, does the RB4011iGS+5HacQ2HnD-IN do continuous 160, 80+80, or both? Does disabling the chains you mentioned force it in continuous 160 mode?
I will utilize the rest of the information you provided, once I achieve selecting the channel I require on the RouterBOARD side.
 
Reinis
MikroTik Support
MikroTik Support
Posts: 57
Joined: Wed Jan 02, 2019 12:14 pm
Location: Latvia
Contact:

Re: Why channel 50 isn't selectable in the 160Mhz band?

Wed Jul 03, 2019 1:08 pm

There appears to be some confusion still. Let me clarify once more that I know that in RouterOS we don't set them via the numerical/traditional way.
I know how to match the channels to frequencies because that information is readily available. I am only referring to them via numerals because it's easier to convey.
When I was replying by "where do you see channels 36, 40, 64 and so forth" what I meant was "where do you see the frequencies corresponding to those channels, because they are not offered". I am not expecting to see channel numbers, I am expecting to see their corresponding frequencies.. and the problem is that half of my options are missing here.
A: The available channels are restricted per country and other settings, like indoor/dfs etc.
You can find interface capabilities for the current configuration running command: /interface wireless info allowed-channels interface=wlan1
And what is allowed for a specific country and settings, running command: /interface wireless info country-info latvia

I am aware of superchannel, however none of my wireless devices are able to even discover the SSID when this option is selected. (Even in 80MHz-wide mode where regulatory-domain normally works)
I am not sure of the "debug" country option however. Assuming it doesn't suddenly vanish in the future, being called debug and all.
A: Are you sure that the interface was running (not in "detecting radar state")? Note that the host device has to have the capability of working in the specific configuration. If the AP is configured to overlap a restricted/not-supported configuration, the host might and will not see the AP.
If you can, please write to support@mikrotik.com to determine exactly what is the issue regarding this.

But, if we are to return to the original question of this thread..
Why is it that the 5170-5330MHz frequencies which exist in the 802.11ac spec and selectable on devices from other vendors, not being offered under any country option in MikroTik devices? (When used in 160MHz mode)
^ This is what I want you to primarily answer me, instead of eluding to a blanket statement called "restrictions".
Other vendors certainly doesn't seem to have those "restrictions", as pe1chl mentioned (being able to select the 160MHz-wide channel within the 5170-5330MHz range on his UBNT device).
A: Thank you for clarifying the issue, we have reproduced it and will fix it as soon as possible.

Just to clarify, does the RB4011iGS+5HacQ2HnD-IN do continuous 160, 80+80, or both? Does disabling the chains you mentioned force it in continuous 160 mode?
I will utilize the rest of the information you provided, once I achieve selecting the channel I require on the RouterBOARD side.
A: RB4011iGS+5HacQ2HnD-IN works accordingly to IEEE 802.11-16/554r4, so the beacons will advertise AP capabilities accordingly to the configuration.

Disabling chains example was for the particular network card (Intel AC 9260), which does not support extended NSS field (that added 80+80MHz support). Most likely it's because the chosen NSS value has to be rounded to the lowest integer, thus the card does not even try to use 160MHz when all chains are enabled on the RB4011.

RB4011 can do 160 and 80+80 at the same time. Note, that interference will impact what rate is selected at a given moment by the AP and Host device. And that you have to set secondary-frequency for 80+80MHz transmission to be enabled

An example, where 160MHz and 80+80Mhz is working at the same time between two RB4011 (This is just an example and not peak performance)
Image

Configuration:
channel-width=20/40/80mhz-Ceee frequency=5180 secondary-frequency=auto frequency-mode=regulatory-domain country=latvia antenna-gain=3
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Thu Jul 04, 2019 2:13 am

Thank you both for the confirmation and the additional info. I will utilize this knowledge when the fix is available.
My sincerest apologies if you feel I was too abrasive with my replies.
 
Reinis
MikroTik Support
MikroTik Support
Posts: 57
Joined: Wed Jan 02, 2019 12:14 pm
Location: Latvia
Contact:

Re: Why channel 50 isn't selectable in the 160Mhz band?

Tue Jul 09, 2019 2:18 pm

Thank you both for the confirmation and the additional info. I will utilize this knowledge when the fix is available.
My sincerest apologies if you feel I was too abrasive with my replies.
A fix regarding 5170-5330MHz 160MHz has been made and will be released in the next beta (current is 6.46beta6, so next public beta release).
The same applies to upcoming Stable/Long-term versions
 
Frostbyte
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 72
Joined: Mon Dec 25, 2017 1:42 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Wed Jul 10, 2019 8:49 pm

A fix regarding 5170-5330MHz 160MHz has been made and will be released in the next beta (current is 6.46beta6, so next public beta release).
The same applies to upcoming Stable/Long-term versions
You guys have been stepping up your game and it deserves to be heard. Thank you for everything. :)
 
gmobilize
just joined
Posts: 5
Joined: Tue Feb 07, 2017 10:04 am

Re: Why channel 50 isn't selectable in the 160Mhz band?

Wed Jul 31, 2019 12:33 pm

Hey,
So I have an Intel 9260 card and tried the mentioned config by disabling 2 out of 4 chains and mentioned Channel configs of eeeeeeeC and 5320MHz and was finally able to achieve the 160MHz connection. However, upon authenticating with the AP i get 1.7 Gbps link speed, but after a few seconds it jumps down to 866.6 Mbps and stays locked there, is this due to some Interference or not being to use all the channel bandwidth?
Would be nice to hear as I have read much of the theory here and big thanks to @reiniss2 for the valuable info.
 
Reinis
MikroTik Support
MikroTik Support
Posts: 57
Joined: Wed Jan 02, 2019 12:14 pm
Location: Latvia
Contact:

Re: Why channel 50 isn't selectable in the 160Mhz band?

Fri Aug 02, 2019 9:09 am

Hey,
So I have an Intel 9260 card and tried the mentioned config by disabling 2 out of 4 chains and mentioned Channel configs of eeeeeeeC and 5320MHz and was finally able to achieve the 160MHz connection. However, upon authenticating with the AP i get 1.7 Gbps link speed, but after a few seconds it jumps down to 866.6 Mbps and stays locked there, is this due to some Interference or not being to use all the channel bandwidth?
Would be nice to hear as I have read much of the theory here and big thanks to @reiniss2 for the valuable info.
Sadly, that's the biggest issue when talking about 160MHz, it takes a lot of space frequency wise which also means it is more sensitive to the interference and other surrounding factors.

We are working on a workaround that will not require disabling chains so devices that does not support NSS Extended field and are 2x2 could also negotiate for 160MHz seamlessly.

Who is online

Users browsing this forum: No registered users and 27 guests