Q23.Marks: +2.0UGC NET Paper 2: Computer Science 2nd January 2026 Shift 1
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: 1-persistent CSMA provides low delay under low load conditions. Reason R: When the channel is free, stations transmits immediately without any random delay, ensuring quick access and minimal delay.
In the light of the above statements, choose the most appropriate answer from the options given below
1.Both A and R are correct and R is the correct explanation of A✓ Correct
2.Both A and R are correct but R is NOT the correct explanation of A
3.A is correct but R is not correct
4.A is not correct but R is correct
Solution
The correct answer is Both A and R are correct and R is the correct explanation of A.
Key Points
1-persistent CSMA is a protocol in which a station transmits immediately when the channel is found to be idle, without any random delay.
This ensures minimal delay under low load conditions, as stations can access the channel quickly without waiting.
In the given assertion (A), it is correctly mentioned that 1-persistent CSMA provides low delay under low load conditions.
The reason (R) also correctly states that immediate transmission upon finding the channel free leads to quick access and minimal delay.
Therefore, both the assertion and the reason are correct, and the reason is the correct explanation of the assertion.
Additional Information
Key Characteristics of 1-persistent CSMA:
The station continuously senses the channel and transmits immediately when the channel is free.
It provides minimal delay under low traffic conditions but may lead to collisions under high traffic.
Advantages of 1-persistent CSMA:
Ensures low delay when the load is light, as there is no waiting period for transmission.
Simple to implement and provides efficient channel utilization under light traffic.
Disadvantages of 1-persistent CSMA:
High probability of collisions under heavy load due to multiple stations trying to access the channel simultaneously.
Not suitable for environments with high traffic, as collisions can lead to delays and inefficiencies.
Comparison with Other CSMA Protocols:
Non-persistent CSMA: Introduces a random delay before retrying, reducing collisions but increasing delay.
P-persistent CSMA: Stations transmit with a certain probability when the channel is free, balancing delay and collision probability.
