In stop and wait communication from A to B the frame duration is T. immediately upon receiving a complete frame, B sends back an acknowledgement of duration T/4. The propagation time is the same in both directions. It is found that 50% of the time A is waiting and 50% of the time sending the frame.
a) Draw a space-time diagram of the communication use a horizontal time direction.
b) What is the propagation time in each direction in term of T?
c) For the same actual propagation times as in b), and the same bits per frame as in a) and b), if the bits rates were doubled, thereby halving the frame and ack signal durations, what would the new percentage of the time A would be sending a frame?
d) For the same actual propagation times as in b), and the same bits per frame as in a) and b) if the bits rates were doubled, what would be the percentage increases in average delivered data rate?