a. Calculate the bandwidth-delay product, R - dprop. b. Consider sending a file of 800,000 bits from Host A to Host B. Suppose the file is sent continuously as one large message. What is the maximum number of bits that will be in the link at any given time? c. Provide an interpretation of the bandwidth-delay product. d. What is the width (in meters) of a bit in the link? Is it longer than a foot- ball field? e. Derive a general expression for the width of a bit in terms of the propaga- tion speed s, the transmission rate R, and the length of the link m. P26. Referring to problem P25, suppose we can modify R. For what value of R is the width of a bit as long as the length of the link? P27. Consider problem P25 but now with a link of R = 1 Gbps. a. Calculate the bandwidth-delay product, R - dprop. b. Consider sending a file of 800,000 bits from Host A to Host B. Suppose the file is sent continuously as one big message. What is the maximum number of bits that will be in the link at any given time? c. What is the width (in meters) of a bit in the link? P28. Refer again to problem P25. a. How long does it take to send the file, assuming it is sent continuously? b. Suppose now the file is broken up into 20 packets with each packet con- taining 40,000 bits. Suppose that each packet is acknowledged by the receiver and the transmission time of an acknowledgment packet is negligible. Finally, assume that the sender cannot send a packet until the preceding one is acknowledged. How long does it take to send the file? c. Compare the results from (a) and (b). P29. Suppose there is a 10 Mbps microwave link between a geostationary satellite and its base station on Earth. Every minute the satellite takes a digital photo and sends it to the base station. Assume a propagation speed of 2.4 - 108 meters/sec. a. What is the propagation delay of the link? b. What is the bandwidth-delay product, R dprop ? c. Let x denote the size of the photo. What is the minimum value of x for the microwave link to be continuously transmitting? P30. Consider the airline travel analogy in our discussion of layering in Section 1.5, and the addition of headers to protocol data units as they flow down