Information Sharing in Mobile Ad-Hoc Networks: Evaluation of the MIDAS Data Space Prototype

Information sharing in dynamic mobile ad-hoc networks is a challenging task. High data availability in the presence of short and long term disconnections can be obtained by replicating shared data. The number of replicas must however be balanced against the cost of consistency management. In the MIDAS Data Space (MDS) we use optimistic replication together with internal versioning of data; this allows application-specific conflict resolution when reconciling replicas at network mergings. We have made a proof-of-concept implementation to perform experiments and to demonstrate through real-life field tests the usefulness of our design. In this paper we report our results. We have conducted a number of experiments on a small network formed by real devices to obtain a detailed performance evaluation. Using an emulation environment we have analysed and quantified the cost of consistency management, the impact of MDS operations, and the relationship between data availability and replication.