Part A: IEEE $802\mathrm{.}15\mathrm{.}4$ MAC $-$ Limitations and Solutions

Answer the following questions:

Explain why the use of CSMA$/$CA in IEEE $802\mathrm{.}15\mathrm{.}4$ leads to low reliability, unbounded packet delays and no protection against interference$/$fading$.$

Explain how IEEE $802\mathrm{.}15\mathrm{.}4$e solves the following limitations of IEEE $802\mathrm{.}15\mathrm{.}4$: $($i$)$ low reliability, $($ii$)$ unbounded packet delays, $($iii$)$ no protection against interference, and $($iv$)$ frequency selective fading.

IEEE $802\mathrm{.}15\mathrm{.}4$e has a higher capacity than IEEE $802\mathrm{.}15\mathrm{.}4.$ Why?

The slotted version of CSMA has a higher performance $($throughput$)$ than the unslotted version of CSMA. Discuss two possible reasons.

IEEE $802\mathrm{.}15\mathrm{.}4$e supports two channel diversity methods: 'Channel Adaptation' and 'Channel Hopping'. What is the difference between these methods? How do they help avoid interference or poor channels?

Why does IEEE $802\mathrm{.}15\mathrm{.}4$ support both CSMA$/$CA and TDMA $($GTSs$)$ channel access methods?

In IEEE $802\mathrm{.}15\mathrm{.}4$e$,$ a PAN coordinator has the option of enabling 'CAP reduction'. What is the purpose of having only one CAP?

In IEEE $802\mathrm{.}15\mathrm{.}4,$ four links occupy four different Guaranteed Time Slots $($GTSs$).$ However, for IEEE $802\mathrm{.}15\mathrm{.}4$e$,$ these four links occupy only two GTSs$.$ How is this possible?