Analysis of micro-level behavior of ad hoc network MAC

In mobile ad hoc networks (MANETs), protocol behavior is most commonly studied at a macro level: connections are examined to see how their throughput fares through the entire network. In some instances, this level of analysis cannot explain the observed behavior or provide insight necessary to predict behavior in other scenarios. As a result, general solutions to problems such as unfairness which are rooted in low level behavior fail to take into account the basic behavior that causes the problems. In this paper, we use a complimentary approach where we examine behavior at a much lower level, by studying the interactions among two single hop connections in all possible configurations in terms of the relationship between of the senders and receivers. We study these connections using the standard 802.11 MAC protocol, with and without the request to send and clear to send (RTS/CTS) control packets, as well as with a well-known fairness algorithm. We isolate configurations that cause unfairness and inefficient behavior. Understanding the root causes of these problems is a first step towards a more complete understanding of connection behavior in MANETs that will allow developing fair access algorithms that directly target the causes of the observed problems.