MAC schemes for ad-hoc wireless networks

In this paper we propose a comparison between different MAC protocols for wireless ad-hoc networks. Specifically we consider a well-known protocol adopted at the MAC layer, that is the Std IEEE 802.11 and a totally distributed Mac protocol based on a contention phase and a TDMA phase, the Evolutionary-TDMA. Moreover, we propose a new totally distributed TDMA Mac protocol, that based on the information of 1 and 2 hop neighbors permits schedules to be built. This protocol permits conflict-free schedules to be built in the first phase called Control Phase, but there is a Re-distribution phase based on a random function that do not guarantees that schedules are totally conflict-free. The MAC protocol proposed in this work is called Randomized-MAC, because it is based on a random function in the Re-distribution phase. Randomized-MAC is implemented in a well-known simulation tool, NS2. In NS2 we conducted extensively simulation campaigns that permit to conclude that even if schedules built with our schemes are not necessarily conflict-free, Randomized-MAC permits better performance in terms of throughput and delay to be obtained.