Computer Networks · TEE · papers

Q1C · Slotted ALOHA

Final · 5 December 2025

TEE · Actual TEE paper · all questions · current syllabus 702AI0C023

Actual PYQ · Q1C. In a Slotted ALOHA system, the average number of frames generated per frame time is G = 1. Calculate the throughput S. What is the maximum throughput in Slotted ALOHA? [5 marks]

Answer

Given

Protocol = Slotted ALOHA; G = 1 attempts/frame time.

To find

S, 100S and the maximum possible S.

Formula and why

S=G e^{-G}LaTeX: S=G e^{-G}

Select the formula from the protocol name. The exponent is −G because Slotted ALOHA has a T vulnerable period.

Step-by-step solution

Step 1. Calculate the exponent

−1 × 1 = -1.

Step 2. Evaluate the exponential

e^{-1} \approx 0.367879441LaTeX: e^{-1} \approx 0.367879441

Step 3. Multiply by G

S = 1 × 0.367879441 ≈ 0.367879441 successful frames/frame time.

Step 4. Convert to percentage

0.367879441 × 100 ≈ 36.7879%.

Step 5. State the maximum separately

The maximum is 1/(1e) ≈ 0.367879 = 36.7879%, at G=1.

Final answer: S ≈ 0.367879; percentage ≈ 36.7879%; Smax ≈ 0.367879 at G=1.

Source: Final · 5 December 2025, original question paper page 1. Original marks retained; solution independently authored.