A data message of $32$K $8-$bit characters is sent over a two$-$wire half$-$duplex line in packets of length $2$K bytes. Each packet has $10$ control characters per packet. The baud rate is $9600$ Baud. Find the average message delay and channel utilization under the following conditions: Case $($a$)$: No acknowledgments are transmitted. Case $($b$)$: Positive acknowledgments are transmitted, and the next packet cannot be sent until all earlier ones are acknowledged. Assumptions: Turn$-$around time at each end is $150$ ms$.$ The propagation delay is $30$ ms$.$ Acknowledgment packets are $2$ bytes $($not data$).$ No errors are detected. Definitions: Channel utilization is defined as the ratio of the average time spent sending data to the total time required.