Question

Which access method uses a "listen before sending" strategy?

a. Polling
b. Token bus
c. All of these
d. Token passing
e. CSMA/CD

Answer 1

CSMA/CD (Carrier Sense Multiple Access with Collision Detection) is the access method that uses a 'listen before sending' approach, primarily used in Ethernet networks to reduce data packet collisions by checking the medium for activity before transmitting.

Step-by-step explanation:

The access method that uses a "listen before sending" strategy is CSMA/CD (Carrier Sense Multiple Access with Collision Detection). This method is employed in Ethernet networks where devices on the network listen to the cable before transmitting data to ensure no other device is transmitting at the same time. If the medium is detected as idle, the device can proceed with sending its data. If not, it waits for a random period of time before attempting to transmit again. This process helps to minimize data packet collisions on the network. Neither polling, token bus, nor token passing employs this "listen before send" approach.