Quantifying Content Consistency Improvements Through Opportunistic Contacts

The sharing and dissemination of online content is one of the main purposes of social network applications, and the amount of content accessed through them, in particular through portable devices such as smartphones and PDAs, is expected to increase. Consumption of online content, however, does not require a continuous online presence. Content can be downloaded, consumed, modified, and uploaded at different times. An opportunity to improve a user's access to up-to-date information from its own social network is to take advantages of opportunistic contacts between mobile devices, \ie without waiting for connectivity to the network infrastructure. In other words, users of a social network application may receive more fresh content with no extra infrastructure deployment, simply by communicating with mobile devices of other users, in a delay-tolerant manner. Assessing the magnitude of this improvement is, however, challenging. For example, the frequency and patterns of such contacts are partly a function of the social connectivity of users, and so will be the availability of relevant information to share and more importantly the willingness to share that information. All these influence in non-trivial ways the gains that can be realized through opportunistic contacts. The paper's main contribution is in providing a quantitative handle through which these gains can be estimated, while accounting for the above factors.