Gateforum Test Series: Computer Networks - Lan Technologies

Question

Let cluster of stations share 48kbps of pure aloha channel. Every station outputs frame of length 1024 bit in every 50 seconds. Then what is the maximum value of number of stations?

Comments

@Utkarsh Joshi student hun :P

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oh okay! :)

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Thanks mate! :)

Answer 1

Since its pure aloha. So max Bandwidth utilization is 18% of 48Kbps.
And its given, Each station transmits

1024 bits in 50 seconds

$\therefore$ In 1 second --- $\frac{1024}{50}$ bits
Let's say there are N stations.

So N*$\frac{1024}{50}$=18% of 48*1000

N=$\left \lfloor 421.875 \right \rfloor$

$\therefore$ N=421

Comments

for pure aloha efficiency = 18.4%

means 0.184 x 48 Kbps=8.832 kbps

1024/50 = 20.48

20.48 x N = 8.832 x 10$^{3}$

N= 431.25

so , No of Stations, N=431

That .4 in efficiency makes a lot of difference

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Yes.. great

Answer 2

@minipanda @utkarsh

Aloha is not in syllabus now noe?

Please suggest

Comments

The official Gate syllabus doesn't mention it but it's safer to know a bit..