Question
Imagine that you have trained your St. Bernard, Bernie, to carry a box of 30 flash drives instead of a flask of brandy. These flash drives each contain 64 gigabytes. The dog can travel to your side, wherever you may be, at 15km/hour. For what range of distances does Bernie have a higher data rate than a transmission line whose data rate (excluding overhead) is 150 Mpbs?
Explanation / Answer
The dog can carry 30*64 gigabytes.(i.e, 1920 gigabytes or 15360 gigabits). A speed of 15 km/hour which equals to 0.004167km/sec. let the range of distance be x km. The time to travel a distance of x km is (x km) / (0.004167 km/sec)=239.98*x sec. Which is approximately equals to 240*x sec. which can yield a data rate of (15360 /(240*x)) gigabits/sec. (i.e 64/x gigabits/sec=64*1024/x megabits/sec=65536/x megabits/sec). We have to find out a range of distance whose data rate is higher than the transmission line. Therefore, 65536/x > 150 which gives x < 65536/150 =436.9. Therefore, x < 437 km( x lessthan 437 km). The range of distance must be lessthan 437 km(436.9km) to obtain datarate greater than 150 Mbps.(0