Replica Degree Maintenance
RDM

Proactive replication strategies, which generally require positioning systems on client devices and significant processing resources for predicting node disconnections, are unsuitable for dense MANETs.
REDMAN proposes an original lightweight RDM facility that works to maintain unchanged the replication degree decided for each shared resource, without guaranteeing absolute consistency, i.e., it is possible to have time intervals when the requested replication degree differs from the actual number of replicas in the dense MANET. In other words, RDM only aims at maintaining consistency likelihood for the chosen resource replication degree, with the relevant pro of significantly limiting the overhead on participant nodes.
The replica manager is in charge of enforcing the needed replication degree and of maintaining information about all shared resources available in the dense MANET (Shared Resource Table - SRT). For any shared resource, the corresponding SRT entry includes the associated replication degree and weakly consistent information about the nodes where the resource is currently replicated.
When a delegate enters a dense MANET, it communicates the metadata of the shared resources to the replica manager, which decides the replication degree to enforce by considering the hint about resource criticality and the number of current participants in the dense MANET. Future work will improve the replica manager decision capability, by taking into account additional indicators such as the current and average network load. Afterwards, the manager creates new SRT entries for the newly arrived resources; any entry contains the enforced replication degree and weakly consistent information about the nodes currently hosting replicas for that resource. Finally, the manager commands the delegates to start the replication operations.
After the initial replica distribution performed by RD, RDM simply works reacting when resource delegates leave the dense MANET. Three different cases may occurr: