2704N router and WiFi channels

[#1]

Hi,
I did a quick search for 'channels' but after a few pages of results it doesn't seem like anyone else has asked.
I'm fairly new to plusnet and they sent me a 2704N router.
I'll save my rant about 100 Mb/s ports for another day 
I've run into some confusion to do with selecting the WiFi channel.
Firstly, all seems well when I choose "up to 54 Mb/s" or "up to 144 Mb/s", and select any channel from the list.
I've got an app on my android phone that displays all the wifi signals it can find and the channel detected correlates with the channel I select from the options.
There's also this command I can use in windows: netsh wlan show networks mode=bssid
However, when I choose "up to 300 Mb/s", it only ever appears to use channel 1 or 11, regardless of my choice in the settings.
I've tried to do some research on the matter, and I've found some information about 20 MHz, 40 MHz, Guard Interval, Spatial Streams, 1x1, 2x2, blah.
The numbers seem to line up with row 15 of the table found in this wikipedia article.
Despite all that, I've not found anything that could explain why the "up to 300 Mb/s" would be stuck at channel 1 or 11, ignoring my selection.
Any ideas?

[#2]

Hi psymon,
Welcome to the forum btw. What a shame that no-one else manage to pick up your post a while back. Anyway see https://community.plus.net/forum/index.php/topic,141847.0.html ;  Not a solution yet I'm afraid.

[#3]

Thanks Anotherone,
Glad to see others looking for an answer.
I'm waiting on a reply to a support ticket about this.
I'll update once I've got more.

[#4]

Please do, it will be interesting to see what they say, if anything at all constructive
What version firmware do you have on yours?

[#5]

3 - Firmware version: 7.273.1_F2704N_Plusnet
4 - Board version: F@ST2704N

[#6]

When I find out what firmware v2 is supposed to fix, I'll post about it.

[#7]

Much appreciated!

[#8]

No Wifi fixes in firmware v2 I'm afraid, just MTU issues.

[#9]

Sad face :C
Thanks for the insider info.
I'm still waiting for a reply on my ticket, keeps getting put on hold.

[#10]

Perhaps the behaviour is intended to prevent your use of 40MHz bandwidth from occupying the entire available spectrum. If your 40MHz starts at an end of the spectrum, then there will be room for a non-overlapping 20MHz channel at the other end. Of course having the primary (20MHz) channel in the middle and choosing whether the secondary channel is above or below would take up the same number of channels, but that would require an extra setting drop-down box.

[#11]

I finally got an answer.

Quote

i can confirm when using the upto 300mbps setting on the router it submits this over the 40MHZ bandwidth which spreads over multiple channels, which is why the number of channels that can be used on this setting are limited

Can't say I'm entirely happy with it.
If the channel selection is 'limited' at 40MHz, why do we still have the optional to choose a channel?

[#12]

That sounds like a BS reply to me, and wouldn't explain why people are having the issues they are.
On 20MHz the signal spreads over 2 channels either side in the UK we can use channels 1 to 13.
On 40MHz it spreads over 4 channels either side which limits the choice from channel 3 to channel 11. It can be argued that choosing anything other than 3 or 11 would be antisocial. In any event channel 1 on 40MHz shouldn't happen.

[#13]

I replied with a question very similar to what you've said, Anotherone.
I'll be back here once they answer that.

[#14]

Using 40MHz, you'd select a primary (20MHz) channel, and then the secondary channel would be the next 20MHz either above or below the primary channel. The primary channel would be the only channel used by 11g devices or 11n devices set for 20MHz only operation. Of course, if the primary channel is near the lower end, the secondary channel can only be above, and if the primary channel is near the top end of the spectrum, there's only room for the secondary channel to be below the primary.
Some wireless routers will have a setting for you to choose whether the secondary channel is above or below, it's in the Sagemcom manual for the generic firmware, but the setting is not available in the Plusnet firmware.

[#15]

Thanks for that further clarification ejs, very helpful. The Plusnet firmware seems as though it won't do the automated choice never mind a user choice being available