Consider a bus topology with 4 stations given below: Suppose the propagation time between any two adjacent stations is 2ms, and the bandwidth of the bus is x Mbps (where x is the last digit of your student ID number, set x = 10 if it is 0). (a) In order to implement collision detection, what is the minimum frame size for the network? (4 marks) (b) Suppose stations A and C start transmitting at time Os and Ims respectively. How many bits have they sent out before detecting the collision? Illustrate the situation using a time diagram. (5 marks) (c) Assume ACK is not used. With collision detection, a station can know the transmission is successful once it completes sending. If collision is detected, the station further transmits 1ms of data before stopping and backoff. If 1-persistent CSMA/CD is used, determine the individual finish time (in terms of ms) of the frames below, i.e. the time when a station successfully sends out the entire frame. Station A B D Ready at (ms) Length (ms) 15 18 12 13 0 10 15 30 Backoff (ms) 10 6 15 30 (8 marks) (d) Repeat part (c) when non-persistent CSMA/CD is used. Determine the individual finish time (in terms of ms) of the frames. (8 marks) Hint for (c) and (d): Don't forget the propagation delay on the bus. Use a time diagram for analysis.