Question

Q.20 The distance between two microwave towers,
with link capacity 100 Mbps, is 24 km and the
speed of the signal is 3 x 108 m/sec. If the frame
size is 16 Kb in the stop-and-wait protocol, what
is the approximate link utilization?
Assume that the acknowledgment packets are
negligible in size and there are no errors during
communication.
(a) 33%
(b) 50%
(c) 66%
Jet 75%
[DRDO-2008]
ect matter to MADE EASY Publications, New D​

Answer 1

Answer:

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*106 = 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

Therefore, Link Utilisation  = 50%