Modeling the interactions between MAC and higher layer

Abstract

We propose a new framework for worst-case performance evaluation of MAC protocols for wireless ad hoc networks. Given a protocol, its performance metrics and a network topology, our framework first generates MAC scenarios which achieve poor performance at MAC level. In order to evaluate the impact of these MAC scenarios on the end performance, we model the interactions between MAC interface and the MAC layer using a state transition graph and generate high-level scenarios using enumeration techniques. These high-level scenarios can be simulated and compared with heuristics developed by others to identify high-level scenarios that are expected to lead to the worst-case end performance. In order to demonstrate its usefulness, we use our framework to evaluate the worst-case performance of IEEE 802.11 DCF protocol by generating a library of MAC- and high-level scenarios. We simulate the high-level scenarios to demonstrate that the scenarios we generate exhibit the worst performance among all the scenarios, including those generated by using heuristics recently proposed by other researchers.