Supporting Cooperative Caching in Disruption Tolerant Networks

Abstract

Abstract-Disruption Tolerant Networks (DTNs) are characterized by the 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 effective data access to mobile users. In this paper, we propose a novel approach to support cooperative caching in DTNs, which enables the sharing and coordination of cached data among multiple nodes and reduces data access delay. Our 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. We propose an effective scheme which ensures appropriate NCL selection based on a probabilistic selection metric, and coordinate multiple caching nodes to optimize tradeoff between data accessibility and caching overhead. Extensive trace-driven simulations show that our scheme significantly improves data access performance compared to existing schemes.

Forwarding redundancy in opportunistic mobile networks: Investigation and elimination

“…Some schemes predict node contact capability by estimating their co-location probabilities [20]. Some others [1], [10], [11] exploit node contacts as stochastic process for better prediction accuracy, based on experimental [14] and theoretical [2] analysis on contact characteristics.…”

Comet: Decentralized Complex Event Detection in Mobile Delay Tolerant Networks

“…Typically, routing strategies exploit connectivity patterns, node mobility patterns, packet replication, and social affinity for achieving effective packet delivery [5], [28], [3]. Unfortunately, research on building applications and systems on DTNs has thus far been confined to simple web applications, distributed file systems, and caching [29], [30], [9]. This paper is a step towards closing this critical gap.…”

“…Research on DTNs has primarily focused on routing issues either for unicasting or for multicasting [5], [3], [6], [7], [8]. Only recently have researchers started to study issues such as caching for DTNs [9].…”

A Reliable and Efficient Encounter-Based Routing Framework for Delay/Disruption Tolerant Networks

“…Concerning the nodal mobility for prediction, as pointed out in [20], our interest focuses on the routing schemes in the branch 2 exploring the nodal encounter history as stochastic process for prediction [13], different from those in another branch making prediction based on their mobility patterns [21]. It is known that, apart from the number of encounters [10] and encounter duration [22] adopted by previous works, the intermeeting time [13], [23] as another important factor 3 measures how regular pairwise nodes will encounter.…”