Correct Answer: B
Explanation
The main characteristic of the 6 GHz band that is true among the given options is that in North America, the 6 GHz band offers more 80 MHz channels than there are 40 MHz channels in the 5 GHz band. This characteristic provides more spectrum availability, less interference, and higher throughput for wireless devices that support Wi-Fi 6E Wi-Fi Enhanced (Wi-Fi 6E) is an extension of Wi-Fi 6 (802.11ax) standard that operates in the newly available unlicensed frequency spectrum around 6 GHz in addition to existing bands below it. Some facts about this characteristic are:
In North America, there are up to seven non-overlapping channels available in each of three channel widths (20 MHz, 40 MHz, and 80 MHz) in the entire unlicensed portion of the new spectrum (5925-7125 MHz). This means there are up to 21 non-overlapping channels available for Wi-Fi devices in total.
In comparison, in North America, there are only nine non-overlapping channels available in each of two channel widths (20 MHz and 40 MHz) in the entire unlicensed portion of the existing spectrum below it (2400-2483 MHz and 5150-5825 MHz). This means there are only up to nine non-overlapping channels available for Wi-Fi devices in total.
Therefore, in North America, there are more than twice as many non-overlapping channels available in each channel width in the new spectrum than in the existing spectrum below it.
Specifically, there are more than twice as many non-overlapping channels available at 80 MHz width (seven) than at 40 MHz width (three) in the existing spectrum below it.
The other options are not true because:
Less RF signal is absorbed by objects in a 6 GHz WLAN: This option is false because higher frequency signals tend to be more absorbed by objects than lower frequency signals due to higher attenuation Attenuation is a general term that refers to any reduction in signal strength during transmission over distance or through an object or medium . Therefore, RF signals in a 6 GHz WLAN would be more absorbed by objects than RF signals in a lower frequency WLAN.
The 6 GHz band is fully backward compatible with existing bands: This option is false because Wi-Fi devices need to support Wi-Fi 6E standard to operate in the new spectrum around 6 GHz . Existing Wi-Fi devices that do not support Wi-Fi 6Estandard cannot use this spectrum and can only operate in existing bands below it.
Low Power Devices are allowed for indoor and outdoor usage: This option is false because Low Power Indoor Devices (LPI) are only allowed for indoor usage under certain power limits and registration requirements . Outdoor usage of LPI devices is prohibited by regulatory authorities such as FCC Federal Communications Commission (FCC) is an independent agency of United States government that regulates communications by radio, television, wire, satellite, and cable across United States . However, outdoor usage of Very Low Power Devices (VLP) may be allowed under certain power limits and without registration requirements.
References: https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-6e
https://www.wi-fi.org/file/wi-fi-alliance-spectrum-needs-study
https://www.cisco.com/c/en/us/products/collateral/wireless/spectrum-expert-wi-fi/prod_white_paper0900aecd80
https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/82068-power-levels.html
https://www.wi-fi.org/file/wi-fi-alliance-unlicensed-spectrum-in-the-us
