Carrier sense multiple access with collision detection
（重定向自Jam signal）
![Simplified Algorithm of CSMA/CD. Station checks if another station is transmitting, if not it sends the first bit of information. If no collision is detected it will continue to send the other bits of information while continuously checking if a collision has been detected. If a collision is detected it will calculate a random amount of time to wait and start the process again. If the maximum amount of attempts is reached then no transmission is possible and it will be aborted.](/Images/godic/202501/21/CSMACD-Algorithm.svg2327.png")
Carrier sense multiple access with collision detection (CSMA/CD) is a media access control method used most notably in local area networking using early Ethernet technology. It uses a carrier sensing scheme in which a transmitting data station detects other signals while transmitting a frame, and stops transmitting that frame, transmits a jam signal, and then waits for a random time interval before trying to resend the frame.