DAR: Distributed Adaptive Service Replication for MANETs

Mobile ad hoc networks (MANETs) can be used to provide mobile users temporary infrastructure to use services such as database retrieval service when traditional infrastructure-based networks are unavailable in infrastructure-less situations (e.g. after a destructive disaster like an earthquake). The challenging task in such dynamic environments is how we can improve the service availability. An effective strategy is replicating a service at some nodes distributed across the network. However, service replication can considerably impact the system energy consumption. Since mobile devices have a limited amount of battery, a dynamic and efficient service replication is necessary to support such environments. In this paper, we propose a distributed service replication scheme for achieving high service availability with reasonable energy consumption for MANETs. The proposed method called distributed adaptive service replication (DAR) divides the whole network into disjoint zones of at most 2-hops in diameter and builds a dynamic replication mechanism which puts replicas only in zones with high service demand. Through simulations, we have confirmed that our approach can achieve higher service availability and lower energy consumption than an existing method.