Q12.Marks: +2.0UGC NET Paper 2: Computer Science 7th Dec 2023 Shift 2
Which of the following are example of CSMA channel sensing methods?
(A) 1-persistent
(B) 2-persistent
(C) p-persistent
(D) 0-persistent
Choose the correct answer from the options given below:
1.(A), (B) and (D) Only
2.(A), (C) and (D) Only ✓ Correct
3.(B), (C) and (D) Only
4.(A), (B) and (C) Only
Solution
The correct answer is (A), (C) and (D) Only
EXPLANATION:
The CSMA (Carrier Sense Multiple Access) channel sensing methods are:
1-persistent CSMA: The station continuously senses the carrier, and if the channel is idle, it sends the frame immediately with a probability of 1 (i.e., persistence value of 1). If the channel is busy, the station waits until it becomes idle.
p-persistent CSMA: The station senses the channel, and if it is idle, it sends the frame with a probability p (0 < p ≤ 1). If the channel is busy or the frame is not sent, it waits for a certain period and tries again.
0-persistent CSMA: The station senses the channel, and if it is idle, it sends the frame immediately with a probability of 0. This means it does not persistently check the channel if busy but waits a random period before retrying.
Therefore, the correct answer is (A), (C), and (D) Only.