x = 5

Question 4 (30%) Suppose you send a 100 Mb file to your friend at 5 km away. The channel data rate is 10 Mbps and the propagation speed is 2 x 108 ms. Stop-and-Wait ARQ is used in the transmission. Each frame carries 1500 bits of data plus 24 bits of overhead (header + trailer). ACK frame has a fixed size of 50 bits. The queuing and processing delay along the path can be neglected. Note: Use 1K = 1000, 1M= 1000K and 1G = 1000M. (a) How many data frames will be sent? What are the sizes of the frames? (5%) (b) What is the time to confirm the first frame is correctly received by the receiver? (8%) (c) Continued from (b), how long does it take to complete the file transmission? (5%) (d) If any frame is corrupted, how can it be recovered? (4%) (e) Assume there are 2 frames lost in every 100 frames sent, no frame lost if less than 100 frames sent, and the last frame is not lost. By using a timeout value of (10 * x) ms (x is the 5th digit of your student ID number, set x = 10 if the 5th digit is 0), calculate the total time required for the process to complete. (8%)