Analysis of Optimal Query, Fairness and Replication for DHT-based Mobility Management

A considerable amount of research on distributed hash table (DHT) based mobility support schemes, which are highly user scalable and load balanced, has been done. However these schemes have shortcomings in query performances and network scalability. It is because although routing of overlay itself is effective, there is inconsistency between logical and physical topologies, so the actual physical network performances are not necessarily efficient. In this article, we introduce a replication technology based DHT-based mobility management. Then all queries from any subnet can get responses as early as possible, i.e. the query distances are reduced, and the scopes of effect of topological inconsistency are limited. We investigate the effect of the number of mapping replicas on query performances for DHT-based mobility management. And we find that replicating mobile nodes´ mappings in proportion to their call-mobility-rates (CMRs) minimizes the query delay, and also ensures fairness in the query load distribution. Moreover, we propose a DHT and proportional replication based mobility management scheme, called DPRMM. The numerical results show that DPRMM optimizes the query delay and overhead performances of dDHT, and achieves better fairness and network scalability than MIPv6 and dDHT.