Consider a 50 Kbps satellite channel with a 500 milliseconds round trip propagation delay. If the sender wants to transmit 1000 bit frames, how much time will it take for the receiver to receive the frame?
- A. 250 ms
- B. 20 ms
- C. 520 ms
- D. 270 ms
Answer: D. 270 ms
Explanation: Transmission time $T_t = 1000 \text{ bits} / 50 \text{ kbps} = 1000 / 50000 = 0.02 \text{ s} = 20 \text{ ms}$.\nPropagation delay (One way) = RTT / 2 = $500 / 2 = 250 \text{ ms}$.\nTotal time = $T_t + T_p = 20 + 250 = 270 \text{ ms}$.