The GATE Grind

GATE 2017 CS (CS2) – Question 44

Computer Networks · Data Link Layer: Error Detection, Medium Access Control, Flow Control · 2 marks · Multiple choice

A binary code has exactly four valid words: 00000,01011,10101,11110. Let p be minimum Hamming distance and q maximum correctable bit errors. Find p,q.

  1. p=3,q=1
  2. p=3,q=2
  3. p=4,q=1
  4. p=4,q=2

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (A) p=3,q=1

Explanation

Pairwise XOR weights are 3,3,4,4,3,3, so dₘᵢₙ=p=3. Unique correction of t errors requires 2t+1≤dₘᵢₙ, giving $q=\lfloor(3-1)/2\rfloor=1$. Thus A.

More Data Link Layer: Error Detection, Medium Access Control, Flow Control questions

All Data Link Layer: Error Detection, Medium Access Control, Flow Control questions →