EXERCISE 1 (7.5 points) - A shared medium of length L=800m operating at 1Gbit/s is used by 5 equally spaced stations (i.e., the distance between two consecutive stations is 200m ), numbered from 0 a 4 as depicted in the figure below. The propagation speed of the signal along the medium is 2108m/s. All frames transmitted by the stations have a constant length of D=100 bytes. a) Based on the above-mentioned data and assuming no carrier sense/collision detection latency, does the scenario guarantee that in a CSMA-CD multiple access protocol every collision is always detected? If yes, why? If no, how long should frames be to provide such guarantee? ( 2 points) b) Repeat point a) assuming that a carrier sense latency CS=2 us and a collision detection latency CD=3 us are introduced (1 point) c) Consider the scenario described at point a) and assume that, at time t=0, both stations \#0 e \#2 start transmitting a frame. All the other stations remain silent. Which stations identify that a collision has occurred ( 2.5 points)? How long does station \#1 sense the channel as occupied (indicate start and end times of the busy channel period)? (2 points)