Cooperative Caching for Efficient Data Access in Disruption Tolerant Networks
Disruption tolerant networks (DTNs) are characterized by low node density, unpredictable node mobility, and lack of global network information. Most of current research efforts in DTNs focus on data forwarding, but only limited work has been done on providing efficient data access to mobile users. A novel approach is proposed to support cooperative caching in DTNs, which enables the sharing and coordination of cached data among multiple nodes and reduces data access delay. The basic idea is to intentionally cache data at a set of network central locations (NCLs), which can be easily accessed by other nodes in the network. To propose an efficient scheme that ensures appropriate NCL selection based on a probabilistic selection metric and coordinates multiple caching nodes to optimize the tradeoff between data accessibility and caching overhead. Extensive trace-driven simulations show that this approach significantly improves data access performance compared to existing schemes.