CENG 210 Data Link Layer - Random Access Protocols

The maximum throughput when using pure ALOHA protocol can be achieved when the average number of submitted frames G equals

• 0.25

• 0.5

• 1

• 2

Compared with pure ALOHA, slotted ALOHA protocol may be preferred to be used when the number of stations increases with overlapping communication ranges.

• True

• False

An increase in the round trip time of a frame and its acknowledgment will lead to a decrease in the timer value set by the sender.

• True

• False

The multiple access protocol that suits accessing shared wireless channels is

• CSMA

• CSMA/CD

• CSMA/CA

• none of them

The vulnerable time in pure ALOHA and slotted ALOHA is directly proportional with the

• round trip time

• frame time

• backoff time

• timeout value

The frame time refers to the (a)   time of the frame.

In random multiple access protocols, the sending station might encounter a random waiting time to be able to send its data.

• False

• True

In a network using the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol, what is the primary action taken when a collision is detected on the network?

• The device stops transmission and retries after a random delay

• The device stops transmission and waits for a fixed amount of time

• The device continues transmission and ignores the collision

• The device immediately shuts down to avoid further collisions

Which of the following best describes the role of "Carrier Sense" in the CSMA/CD protocol?

• It detects when a collision has occurred

• It ensures that a device sends data without waiting

• It checks if the transmission medium is idle before sending data

• It terminates the connection after successful transmission

Which of the following is a key difference between CSMA/CA and CSMA/CD?

• CSMA/CA is used in wired networks, while CSMA/CD is used in wireless network

• CSMA/CA involves detecting collisions after they occur, while CSMA/CD avoids them before transmission

• CSMA/CA attempts to avoid collisions before transmission, while CSMA/CD detects and handles collisions after they occur

• CSMA/CA is used for real-time applications, while CSMA/CD is used for file transfers