Consider a network with three laptop computers. Computer 1 sends packets to computer 3 using wireless links. The two possibilities are: computer 1 sends directly to 3, or sends to 2 and 2 sends to 3. Based on the distances between the computers, we assume in this model that the Bit Error Rate (BER) for the link (1,2) and (2,3), respectively is denoted as BER(1,2), BER(2,3), and is equal to BER(1,2) = BER(2,3)=1/10*BER(1,3).
Assume further that the packets that are received in error are retransmitted and are not removed from the head of the queue until correctly received. Assume computer 1 has to transmit a file that contains 10000 packets. Simulate the system and determine average end-to-end transmission delay for a correct reception for a packet at the destination, and the cumulative distribution function for the end-to-end delay for the two cases considered. For this file transfer application, in order to determine the end-to-end delay, you may consider that the file (all packets) is created at the beginning of the simulation (time 0), and the acknowledgement for a correctly received packet is instantaneous.