Briefly describe the working principle of CSMAQ/CD

CSMA/CD: Carrier Sense Multipoint Access Collision Detection Protocol
(1) Multi-point access: The computer is connected to a bus in a multi-point access manner
(2) Carrier monitoring: Before each station sends data, check whether there are other computers on the bus sending data. If so, do not send data for the time being
(3) Collision detection: The computer detects the signal voltage on the channel while sending data. When it detects that the voltage swing value of the signal exceeds a certain threshold value, it is considered that at least two stations on the bus are sending data at the same time, indicating that a collision has occurred. Once a collision is found on the bus, it stops sending immediately, and then waits for a random length of time to send again.
特徴: Multi-point access, listen first and then send, listen while sending, stop sending when colliding, and resend randomly.