Question $1(10$p$)$ Consider that DFWMAC$-$RTS$/$CTS$/$ACK $($Method $2)$ is used in WLAN. Answer the

following questions

a$)$ Assume that every station has $5$ MDS packets ready to be transmitted. Find the maximum throughput

for Method $2,$ given that the maximum CTS NAV $=4084s$ and each station has at least one MDS to

transmit. Note that RTS and CTS can reserve the amount of time for data packets to be transmitted

at once.

b$)$ There are three stations $A,B,$ and $C$ in a wireless LAN that uses the above protocol. Assume that the

backoff time of node $A$ is $20s,$ node $B$ is $30s,$ and node $C$ is $10s.$ The arrival packets $($including

headers and payload$)$ are $30s$ long and their available time are shown as arrows in the following figure.

Demonstrate events for each node $($e$.$g$.,$ DIFS$/$SIFS$/$PIFS$,$ RST$/$CTS$/$ACK$,$ backoff time, collision, and

data.$)$

Figure $1$: Time Diagram of DCF MAC with RTS$/$CTS $-$ Question.