$8)$ A communication networks uses Go$-$Back$-$N ARQ protocol, the

probability of receiving the first frame in error depends on:

$($a$)$ data rate

$($b$)$ frame length only

$($c$)$ Both frame length and

BER $($d$)$ BER only

$8$

$($a$)$

$($b$)$

$($c$)$

$($d$)$

$9)$ A communication link has a bit error rate BER$=0\mathrm{.}1.$ Using a frame

length of $1000,$ the probability of receiving a frame in error is given

by:

$($a$)1$

$9$

$($b$)0\mathrm{.}1($c$)1-(1-0\mathrm{.}1)1000$

$($a$)$

$($b$)$

$($c$)$

$($d$)1+(1-0\mathrm{.}1)1000$

$($d$)$

$10)$ A large message of $1$ Mbits is transmitted over two hops. The

transmission line in each hop has a bit error rate of BER$=10-6..$ The

number of bits needed to get $2$ Mbits across the first hop correctly is

approximately:

$($a$)1$ Mbits $($b$)2$ Mbits

$($c$)4$ Mbits $($d$)3$ Mbits

$10\mathrm{.}1($a$)$

$($b$)$

$($c

$($d$)$

The message is broken up into $20$ equal$-$sized packets that are

transmitted separately. The total number of bits transmitted over the