-Spectrum:

 

The cloud resides beyond the visual borders of the arc spectrum of light in the sky.

WiFi waves are traceable in the radio frequency spectrum.
Wireless local area network channels using IEEE 802.11 protocols are sold mostly under the trademark WiFi.

Each channel on the 2.4 GHz spectrum is 20 MHz wide. The channel centers are separated by 5 MHz, and the entire spectrum is only 100 MHz wide total. This means that the 11 channels have to squeeze into the 100 MHz available, and in the end, overlap. The three WiFi channels 1, 6 and 11 have no frequency overlap with each other. Avoid co-channel interference:

/etc/hostapd/hostapd.conf

####>>>>>———>

interface=wlan0
driver=nl80211
ssid=\/\/iFi
channel=6  # 1,6,11,1 each node different channel
hw_mode=g
macaddr_acl=0
auth_algs=1

####<———