What protocol do Ethernet devices use to detect and prevent collisions on half-duplex interfaces?

Ethernet devices utilize the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol to manage access to the shared transmission medium and prevent collisions in half-duplex interfaces. In a half-duplex environment, devices can either send or receive data but cannot do both simultaneously.

CSMA/CD works by having devices listen to the network to determine whether the medium is free (carrier sense) before transmitting data. If a device detects that the network is busy, it will defer its transmission until the channel is clear. During the transmission, if two devices transmit at the same time, a collision occurs. The CSMA/CD protocol includes a mechanism for devices to detect that collision. When a collision is detected, each device stops transmitting immediately and waits for a random backoff period before attempting to transmit again. This process reduces the chance of further collisions and ensures more efficient use of the network.

In contrast, the other protocols mentioned do not apply to Ethernet half-duplex communication. CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) is mainly used in wireless networks, where collisions cannot be detected but can be avoided through other methods. CTS (Clear To Send) and RTS (Request To Send) are control messages used within the context of wireless communication