Available channels on the 5 GHz band using 160Mhz channel width

Available channels on the 5 GHz band using 160Mhz channel width

 

This applies to all devices that support 160 Mhz channel width on its 5 Ghz band.

To be sure that the connection to the 5 GHz band will persist and be able to select a particular wireless channel Smart Connect should be disabled.

When the 160 MHz channel width is enabled, there are only two continuous blocks of channels that you can actually use - these are channels 36 to 64 and 100 to 128 (e.g., available with the Switzerland country code).
Since a large channel width implies that the device will occupy the whole block of channels, there is no point in auto-choosing the channel in the Wi-Fi router's network settings.

 

If the router selects, for example, channel 149, it cannot use a continuous channel block, and the router switches to 80-plus-80 mode by taking two blocks of channels from different parts of the spectrum. Not all clients can use this mode efficiently.

If you do not have a 160 MHz device, you should better exclude the use of this width and set the value to 20/40/80.

If you need to use a 160 MHz width, manually set the channel number to 36, as this width implies that the client covers the whole 36-64 channel block.

If using channel 144 in the 5 GHz band: not all devices support it, so it is excluded from the router's auto channel selection.

If the device cannot see the narrow 144 channel (20 MHz), it will also not see the wider channel blocks (40 MHz, 80 MHz) that include this 144 channel.

Channel 144 with 20 MHz width was previously added to the official IEEE 802.11ac (Wi-Fi 5) standard specification.

Support for a wide range of 132-144 channels (40 MHz, 80 MHz) was later added to the standard.

But most outdated 802.11a and 802.11n clients do not support channel 144.

These clients will use 20 MHz width for 132, 136, 140 channels (for 802.11n 5GHz), and 40 MHz width for 132+136 channels' block.

Currently, many devices comply with the old FCC specifications and cannot work with the 144 channel.

Channels 144 (20 MHz), 143 (40 MHz), and 138 (80 MHz) frequently cannot be used.

 

Why your wireless device can't see the 5Ghz wireless network ?

 

When using a 5 GHz band in the dual-band router, 17 working channels from 36 to 165 are available (frequency range from 5.180 GHz to 5.825 GHz).

By default, automatic channel selection mode is enabled.
Nowadays, many mobile devices are still in use (Samsung, Apple, etc.), which can work on a 5 GHz network, but do not support channels above 140 (and some devices do not support a 5 GHz network on channels above 48).
The same situation is possible when using an outdated Wi-Fi client adapter driver.
If 5 GHz router automatically selects a channel above 140 (e.g., 149), then the mobile device will not see its 5 GHz wireless network.

Connect to the router's web interface, and on Basic=>Network Map=>Router check which channel number your router uses:

 

Try manually setting the channel number below 52 (e.g., 36,40,44 or 48).

You can do this with the 'Channel' dropdown menu (Advanced=>Wireless=>Wireless settings page in the '5 GHz' section)
Then check if a 5 GHz wireless network will be available for connection.

 

Note:

To comply with CE certification in Europe, RE devices with EU FW region do not support Band4: 149-165 (149,153,158,161,165) channels - see this FAQ.