It is possible that the CSMA process will fail and two devices will transmit at the same time. Ethernet and wireless networks use contention-based media access control. If no carrier signal is detected, the device transmits its data.
When the device attempting to transmit sees that the media is in use, it will wait and try again after a short period of time. If there is a signal on the media from another computer, it means that another device is talking. To prevent complete “choking” on the media, these methods use a Carrier Sense Multiple Access (CSMA) process to first detect if the media is transmitting any signal in that moment.
The frames from each machine impact and collide when they meet on the physical media.This contention-based methods allow any device to try to access the medium whenever it has data to send. What are collisions and how they happen? In Ethernet world, the result of two nodes transmitting in the same time.
