Multiple‐resolution content sharing in mobile opportunistic networks

Abstract

AbstractMobile opportunistic network is a kind of delay‐tolerant network that consists of mobile wireless‐enabled nodes and adopts the form of opportunistic transmissions. When nodes are within the radio range, data and contents could be exchanged among the nodes to meet users' requests or subscriptions. Yet because of unpredictable node movements and varied users' interests, the sharing of contents is a challenging problem in mobile opportunistic networks. In this paper, we propose an efficient multi‐resolution content sharing algorithm in mobile opportunistic networks. The algorithm takes data granularity into account and attaches to each content segment a priority weight that combines factors of the node contact pattern and the match between the requests and contents when nodes are in contact. Then, on the basis of the priority weight, the most valued contents of proper resolution level are forwarded to the peer nodes for sharing. Our algorithm also calculates an importance weight for the contents stored in the cache, and content segments with the smallest importance would be transformed into lower resolution to free storage space and hence improve the overall usage of the storage. Extensive experimental results show that our algorithm performs well under extensive conditions. It increases the content delivery rate with little extra cost on message transmissions and delay of requests compared with other algorithms. To the best of our knowledge, this work is the first step on the research on multi‐resolution content sharing in mobile opportunistic networks. Copyright © 2014 John Wiley & Sons, Ltd.