Question

Suppose a 1 Gbps point-to-point link is being set up between the Earth and a new lunar colony. The distance from the moon to Earth is approximately 385,000 km, and data travels over the link at the speed of light (3 x 10⁸ meters per sec.).
Calculate the minimum RTT (two-way propagation time) for the link.(In other words, how long would it take to send a single bit to the moon and immediately bounce it right back to Earth?)

Answer 1

Answer:

The time required to send the data from Earth to Moon will be 1.28s while for a two way communication, to send it back to the earth, it will take double time i.e. RTT = 2.56s

Explanation:

Distance between Earth and Moon = 385,000 km = 3.85 x 10⁸m

Speed of data travel = speed of light ≈ 3 x 10⁸m/s

As, v=d/t

t=d/v

$t=\frac{3.85*10^{8} }{3*10^{8}}$

t=1.28s

RTT = Double of single way time taken = 2x1.28

RTT=2.56s