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A comment on A deep dive into why Wi-Fi kind of sucks.

Re:A deep dive into why Wi-Fi kind of sucks by scurvy on Saturday March 04, 2017 @12:21PM (#13791835)
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.

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Re:A deep dive into why Wi-Fi kind of sucks by dboreham on Saturday March 04, 2017 @04:00PM (#13792899)
Do today's wired networks (1G+/FD/Cat6/fiber) still use CSMA/CD? I was under the impression that they don't.
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Re:A deep dive into why Wi-Fi kind of sucks by hchenji on Saturday March 04, 2017 @07:14PM (#13793772)
No, since wired networks are full duplex and are their own collision domains. No need to do carrier sensing at all.
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Re:A deep dive into why Wi-Fi kind of sucks by scurvy on Monday March 06, 2017 @11:11PM (#13808214)
Not entirely true. You can run half duplex gigabit connections on hubs. Not sure why you would, but you can. IEEE 802.3 covers all Ethernet standards and it still lists CSMA/CD. Largely for historical purposes, but it is in the spec.

Starting with 10gig, full duplex is required so that was the first IEEE speed that did away with CSMA/CD.

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Re:A deep dive into why Wi-Fi kind of sucks by scurvy on Monday March 06, 2017 @11:09PM (#13808207)
Switched networks are full duplex, point-to-point links, so there's no possibility of a collision from the transmitting station. That said, 802.3 still mentions CSMA/CD for half-duplex backward compatibility. Everything 10gig and above requires full duplex though.
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