The distance from Earth to a distant planet is approximately 9 x 107 km. Assume that the frame size is 32 KB and the speed of light is 3 108 m/s. Assume that the bit rate is 32 Mbps. a) (5 points) What is the efficiency (channel utilization) if a stop-and-wait protocol is used? b) (15 points) Suppose we use a window protocol. What should be the window size in frames to achieve the maximal efficiency (channel utilization)? c) (20 points) Plot the efficiency versus the distance when the bit rate is set to 32 Mbps. Discuss this plot. d) (20 points) Plot the efficiency versus the bit rate when distance is set to 9 x 107 km. Discuss this plot.