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The bandwidth of a given medium for transferring the data is 100 Mbps. The user starts with pure aloha for transmission after half of the data is transferred user switched to slotted aloha. Then how much throughput will be gain or loss by the user in the second half?

A

50% loss

B

100% loss

100% gain

D

200% gain

 

i am getting 100% tell me what u are getting

2 Answers

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The throughput of Slotted ALOHA can be calculated using the formula:�=�×�−�Where:

  • S = Throughput
  • G = Number of transmission attempts per frame time

The maximum throughput occurs when G = 1, and it is given by:����=1×�−1=1�≈0.368This means that the maximum throughput of Slotted ALOHA is approximately 36.8%


In the given scenario, the user switches to Slotted ALOHA after half of the data is transferred. This switch will result in an increase in the throughput, leading to a 100% gain in the second half of the data transfer. Therefore, the correct answer is C. 100% gain.
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Given:

  • Bandwidth = 100 Mbps
  • Pure ALOHA efficiency (S) = 1 / (2e)
  • Slotted ALOHA efficiency (S) = e * e^(-e)
  1. Throughput using Pure ALOHA in the first half: Throughput_Pure_ALOHA_1st_half = (1 / (2e)) * 100 Mbps

  2. Throughput using Slotted ALOHA in the second half: Throughput_Slotted_ALOHA_2nd_half = (e * e^(-e)) * 100 Mbps

  3. Throughput using Slotted ALOHA in both halves: Throughput_Slotted_ALOHA_both_halves = (e * e^(-e)) * 100 Mbps

Now, we need to compare the throughputs to determine the gain or loss.

Gain: Gain = Throughput_Slotted_ALOHA_both_halves - Throughput_Pure_ALOHA_1st_half = [(e * e^(-e)) * 100 Mbps] - [(1 / (2e)) * 100 Mbps] = 100 Mbps * (e * e^(-e) - 1 / (2e))

Loss: Loss = Throughput_Slotted_ALOHA_2nd_half - Throughput_Slotted_ALOHA_both_halves = [(e * e^(-e)) * 100 Mbps] - [(e * e^(-e)) * 100 Mbps] = 0

Therefore, the user gains:

Gain = 100 Mbps * (e * e^(-e) - 1 / (2e))

And there is no loss in throughput by switching from Slotted ALOHA in the second half to Slotted ALOHA in both halves.

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