The author kinda bungles his analogy/explanation of collision avoidance and detection. Wireless networks don't use CSMA/CD. They use CSMA/CA. There's a huge difference, and it's one big reason why wireless throughput won't ever come close to PHY speed.
Wired ethernet uses CSMA/CD and it's one of the reasons it won the LAN networking wars of the 80's and 90's.
Wired ethernet uses CSMA/CD and it's one of the reasons it won the LAN networking wars of the 80's and 90's.