Efficient caching scheme for data access in disruption tolerant networks

Disruption Tolerant Networks (DTNs) are characterized by lack of continuous network connectivity because of the limits of radio communication range, sparsity of mobile nodes, shortage of energy resources. There are many researches about data forwarding in DTNs, while limited work on providing efficient data access. In this paper, we propose an efficient cooperative caching scheme, which enables the data query to be satisfied quickly. Our basic idea is to cache data at a set of Proper Nodes (PNs), which can be easily accessed by other nodes in the network. We present a novel algorithm to select the PNs. This algorithm ensures that the PNs are not clustered to damage the data access performance of the whole network. We evaluate our proposed cooperative caching scheme with extensive simulation by using the Sigcomm2009 trace records. The simulation results show that our proposed cooperative caching scheme significantly improves the performance of data access.