Modeling the Order Relations of Events in MANETs

The traditional happened before relation model is inadequate to capture the ordering of events in recent emerging mobile ad hoc networks (MANETs) due to dynamic topology changes. In this paper, we propose a new relation, the extended happened before relation, to model the order relations of events in a MANET. The extended happened before relation is derived not only from the explicit message passing but also from the simultaneous connections and disconnections of wireless channels between mobile nodes. In addition, we present a logical time algorithm called the dual-vector clocks algorithm to record the extended happened before relation between events.