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The distance b/w two microwave towers, with the link capacity 100 Mbps, is 24 km and the speed of the signal is 3 x 10^8 m/sec. If the frame size is 16 Kb in the stop-and-wait protocol, what is the approximate link utilization? Assume that the ACK packets are negligible in the size and there are no errors during communication.

a. 33%
b. 50%
c. 66%
d. 75%
edited | 142 views
+1
Why are we applying the Stop and Wait formula for efficiency here? This is Go-Back-N. Efficiency should ne N/(1+2a), and here sender window size is not given at all?

+1 vote

Data Given as,
Bandwidth = 100Mbps,       Length = 24Km = 24*103,       Frame Size = 16 Kb = 16*103,
Velocity = 3*108

Transmission Time (TT) = Datasize/Bandwidth
= (16*103)/100*10= 160 microsec

Propogation Time (PT) = Length/Velocity
= (24*103)/3*108 = 80 microsec

% Link Utilisation = [TT/(TT+2PT)] * 100
= [160/(160+2*80)] * 100 = 50

Check this...As I have assuming frame size in power of 10 for easy calculation( But it should be in power of 2).

0
Thanks for noticing the error, i updated the question.

1
+1 vote