Question: Consider a sender A that communicates over a wireless channel to a receiver B using SR-ARQ. The round-trip time, intended as the time from the beginning of the transmission of a PDU at terminal A to the complete reception of the corresponding ACK at terminal B is RTT = 500 ms. The transmission bit rate is Rb = 1 Mbit/s. The size of PDU headers and payloads is respectively LO = 100 bits and LD = 4900 bits. The window size of the SR-ARQ protocol is W = 50 PDUs and the channel has a bit error probability of Pbit = 10-4.
a) Compute the normalized throughput S of the given SR-ARQ.
b) Compute a new window size so that the channel pipe is entirely filled with transmitted PDUs and compute the normalized throughput for this case.