Question :
A series of information frames with a mean length of 1000 bits is to be transmitted across a data link 4000km long at a data rate of 2Mbps.
If the link has a velocity of propagation of 2 *108 ms-1 and a BER of 10-4 , determine the link efficiency using the following link protocols:
a) Idle RQ
b) Selective retransmission and a send window of 7
c) Go-back-N and a send window of 127 indicate the effect of bit errors on each of the result obtained.