Suppose users share a $900$ Mbps link. Each user consumes $150$ Mbps when transmitting, and only transmits with probability $0\mathrm{.}2.$ a$)$ How many users can be supported using circuit switching?b$)$ Assume packet switching for the rest of the problem. What is the probability that $7$ out of $10$ users are transmitting?c$)$ What is the maximum number of users, such that the probability of exceeding the link capacity is no more than $0\mathrm{.}01?$ Hint: Gradually increase the number of users and evaluate the probability of exceeding the link capacity for each value of this number. d$)$ What is the average link utilization under the maximum number of users computed in c$),$ defined as $?$