Question 2. Consider the state-transition-diagram for the Stop-and-Wait ARQ in Fig. 5.12. Assume that the transmission times of a frame and an ACK are t, and ta sec. respectively and processing and propagation delays are negligible. Let P, denote the probability that an information frame will be received in error in a transmission and Pa probability that an ACK will be received in error. Determine, Probability distribution of the number of times that the frame will need to be transmitted for the system to make the transition from state (0, 0) to (0, 1). Probability distribution of the number of times that ACK will need to be transmitted for the system to make the transition from state (0,0) to (1, 1). Average time that it will take for the system to make the transition from state (0:0) to state (1, 1). 111) (a) Frame I lost Time-out Time Frame 0 Frame ENQ Frame ! (b) ACK for frame I lost Time-out Time Frame 0 Frame 1 Frame 0 ACK! ACKO FIGURE 5.12 Stop-and-Wait ARQ enquiry frame Question 2. Consider the state-transition-diagram for the Stop-and-Wait ARQ in Fig. 5.12. Assume that the transmission times of a frame and an ACK are t, and ta sec. respectively and processing and propagation delays are negligible. Let P, denote the probability that an information frame will be received in error in a transmission and Pa probability that an ACK will be received in error. Determine, Probability distribution of the number of times that the frame will need to be transmitted for the system to make the transition from state (0, 0) to (0, 1). Probability distribution of the number of times that ACK will need to be transmitted for the system to make the transition from state (0,0) to (1, 1). Average time that it will take for the system to make the transition from state (0:0) to state (1, 1). 111) (a) Frame I lost Time-out Time Frame 0 Frame ENQ Frame ! (b) ACK for frame I lost Time-out Time Frame 0 Frame 1 Frame 0 ACK! ACKO FIGURE 5.12 Stop-and-Wait ARQ enquiry frame
