Consider an Infrastructure BSS with an Access Point and two Mobile Stations, and let’s use AP, M1, and M2 to denote their MAC addresses. Both M1 and M2 are associated with the AP. Suppose M1 wants to send a data frame to M2. When this data frame is relayed by the AP, explain how the AP shall update the four address fields of the data frame.

Consider the subnet in Fig. 3.11.5. Distance vector routing is used and the following vectors have just come in to router C: from B (5, 0, 8, 12, 6, 2); from D(16, 12, 06, 0, 9, 10) and from E(7, 6, 3, 9, 0, 4). The measured delays to B, D and E are 6, 3 and 5 respectively. What is C's new routing table? Give both the outgoing line to used and the expected delay ? A B E Fig. 3.11.5 F D

2. Consider a bus-topology network with five stations. A reservation access method is used. Each station has infinite data to transmit. Each reservation slot has 10 microseconds (note that 1 microsecond = 106 second). For each station, one data transmission sends 1000 bits. The transmission rate over the medium is 10 Mbps. For a station, which is its throughput (in unit "Mbps")?

Computer A uses the Go-back-N ARQ protocol to send a 110 Mbytes file to computer B with a window size of 15. Given each frame carries 100K bytes data. How long does it take to send the whole file (the total time taken from A sending the first bit of the file until A receiving the last acknowledgment)? Given that the transmission rate of the link is 500 Mbps and the propagation time between A and B is 15ms. Assume no data or control frame is lost or damaged and ignore the overhead due to header and trailer.