Update-linearizability: a consistency concept for the chronological ordering of events in MANETs

MANETs are used in situations where networks need to be deployed immediately but no network infrastructure is available. If MANET nodes have sensing capabilities, they can capture and communicate the state of their surroundings, including environmental conditions or objects in their proximity. If the sensed state information is propagated to a database to build a consistent model of the real world, a variety of promising context-aware applications becomes possible. We introduce a novel consistency concept that preserves the chronological ordering of sensed state transition events. Based on this concept, we propose a data replication algorithm for MANETs that guarantees the consistency concept without relying on synchronized clocks and show its correctness. Our simulation experiments show that replicated copies are updated regularly even if the network load in the system is high.