Data communication and networking by forouzan 12.7 Exercise Qn 15

Question

15. In a CDMA/CD network with a data rate of 10 Mbps, the minimum frame size is found to be 512 bits for the correct operation of the collision detection process. What should be the minimum frame size if we increase the data rate to 100 Mbps? To 1 Gbps? To 10 Gbps?

Answer 1

Transmission time of 1 frame = RTT = $\frac{512}{10^7} = 051.2 \mu s$

$T_p = 25.6 \mu s$

Minimum frame size = $2 * T_{p} * BW$

1. Minimum frame size = $2 * 25.6 * 10^{-6} * 100 * 10^6 = 5120 bits$

2. Minimum frame size = $2 * 25.6 * 10^{-6} * 1 * 10^9 = 51200 bits$

3. Minimum frame size = $2 * 25.6 * 10^{-6} * 10 * 10^9 = 512000 bits$