Question

The distance from Earth to a distant planet is approximately 9×109m. What is the channel utilization if a stop-and-wait protocol is used for frame transmission on a 32 Mbps point-to-point link? Assume the frame size is 64 KB.

Answer 1

0.266 %

Step-by-step explanation:

Distance between Earth and distant planet = 9×10⁹ m

Data rate = 32 Mbps

Frame size = 64 KB = 512 Kbits

Propagation speed = Light speed = 3×10⁸ m/s

`\text{Transmission Delay}=\frac{\text{Packet Size}}{\text{Data rate}}\\\Rightarrow T_D=(512)/(32)=16\ ms\\\Rightarrow T_D=0.016\ s`

`\text{Propagation Delay}=\frac{\text{Distance}}{\text{Propagation speed}}\\\Rightarrow P_D=(9* 10^9)/(3* 10^8)\\\Rightarrow P_D=30\ s`

Channel utilization rate

`\text{Utillization}=(T_D)/(T_D+2P_D)\\\Rightarrow text{Utillization}=(0.016)/(0.016+2* 30)\\\Rightarrow text{Utillization}=0.00266=0.266\%`

∴ The channel utilization if a stop-and-wait protocol is 0.266 %