Computer Networks · M2 · mocks

Q1A · Pure versus Slotted ALOHA

M2 mock C

Q1(a)+Q1(b) compulsory; choose any two of Q2/Q3/Q4 · 10 marks attempted

Question. Compare Pure ALOHA and Slotted ALOHA in terms of start time, vulnerable period and maximum throughput. [2 practice marks]

Answer

FeaturePureSlotted
Start timeAny timeSlot boundary only
SynchronizationNo common slots requiredRequired
Vulnerable period2TT
Maximum S1/(2e) ≈ 0.1841/e ≈ 0.368
G at maximum0.51