Problem 3(5+5 pts). A stop-and-wait protocol (read textbook Ch 3.3.3) is a simple data link layer for flow control, in which the sender sends one data frame and then waits for an acknowledgment frame from the receiver before sending the next data frame. We define link utilization U as: U:=TtotalTtrans where Ttrans is the sender's transmission time for the frame and Ttotal is the duration from the sender starting transmission to receiving the acknowledgment frame. Answer the following questions: 1. Assume this protocol achieves 20% link utilization using 1500-bit data frames over a link with a one-way propagation delay of 50msec. We ignore the transmission time for the acknowledgment frame. What is the data rate of this link in bits per second