The objective of this exercise is to explore how high distance and high bitrate affect the efficiency of the stop and wait protocol. The distance from Earth to a distant planet is approximately 5 x 108 km. Assume that the frame size is 20 Kbits and the speed of light is 3 108 m/s. Assume that the bit rate is 20 Mbps. Unless stated otherwise, use the stop and wait protocol in the questions below.

a) (5 points) What is the efficiency (channel utilization) if a stop-and-wait protocol is used? Discuss (is it close to 1? Not close? Is too low? Why?

b) (10 points) Suppose we use a window protocol. What should be the window size in frames to achieve the maximal efficiency (channel utilization)?

c) (10 points) Plot the efficiency versus the distance when the bit rate is set to 20 Mbps. The x-axis will have distances from 0 km to 5 x 108 km. I recommend you to use a graphing tool (e.g., Excel) to prepare data and plot it. We are interested in the impact of distance on the efficiency of the stop and wait protocol. Avoid hand-made plots. Insert here your plot here and discuss it here

d) (10 points) Plot the efficiency versus the bitrate when distance is set to 5 x 108 km. The x-axis will have bit rates from 0 bit/s to 2 Gbps. I recommend you to use a graphing tool (e.g., Excel) to prepare data and plot it. We are interested in the impact of bitrate over the efficiency of the stop and wait protocol. Avoid hand-made plots. Insert your plot here and discuss it here