$110-$ Shows how much time must pass before the stations are

allowed to check the channel for idleness

a$.$ NAV

b$.$ IFS

c$.$ DIFS

d$.$ CTS

e$.$ ACK

$111-$ During the contention window of CSMA$/$CA$,$ if the station

finds the channel busy it

a$.$ Restarts the timer

b$.$ stops the timer

c$.$ resumes the timer

d$.$does nothing

$112-$ What is the fumdamental difference between CSMA$/$CA

and the ALOHA access mechanism, which makes CSMA$/$CA

much more efficient than ALOHA?

a$.$ IFS

b$.$ contention window

c$.$ RTS and CTS

d$.$ carrier

sensing

e$.$ acknowledgement

$113-$ E$1$ line has

telephone lines

a$.16$

b$.24$

c$.30$

d$.32$

e$.48$