Wireless

Has a collision avoidance that avoid Contention Based — wait, listen then talk.

Has 2.4 GHz and 5GHz

2.4 GHz

14 channels, spaced at 5 MHz apart

Support longer range. Wavelength = 5 inches

5 GHz

36 channels, spaced every 20 MHz. Wavelength = 2 inches

[!important]
The larger the waive length, the better the signal will penetrate object. Therefore 2.4 GHz will have better length and range

Waves

The waves acts like light, bounced off mirror surface. We need to space the access points of the same channels as far as possible. Therefore 5 GHz is better for multipoint wireless mesh since it has 36 channels.