Optimal caching time for epidemic content dissemination in mobile social networks

Abstract

To facilitate content distribution and diffusion, efficacious caching strategy plays an important role in content dissemination control, especially in dynamic mobile social networks (MSNs), where contents spreading and accessing rely mainly on opportunistic contacts in physical proximity. Since content dissemination much resembles epidemic dynamics, two caching control schemes, caching at external BS and cooperative innetwork caching, are investigated to assay the system behaviours and performance via epidemic dynamics. When time dynamic is considered, we provide a more realistic scenario where the cost of caching is related to the time duration of caching; hence optimal control theory are exploited to determine the optimal caching time for the content spreading. Moreover, we provide proactive caching analysis as a preventive system response to handle severe outbreak of the epidemic content, which would often cause instantaneous service burden in the system. Finally, virality is shown to be an important content feature when implementing caching. This research, from the aspect of system dynamics, paves novel avenues to content dissemination and caching utilization in mobile social networks.