Density-Aware Routing in Highly Dynamic DTNs: The RollerNet Case
The authors analyze the dynamics of a mobility data set collected in a pipelined Disruption-Tolerant Network (DTN), a particular class of intermittently-connected wireless networks characterized by a 1-D topology. First, they collected and investigated traces of contact times among thousands of participants of a rollerblading tour in Paris. The data set shows extreme dynamics in the mobility pattern of a large number of nodes. Most strikingly, fluctuations in the motion of the roller-bladers cause a typical accordion phenomenon - the topology expands and shrinks with time, thus influencing connection times and opportunities between participants. Second, they show through an analytical model that the accordion phenomenon, through the variation of the average node degree, has a major impact on the performance of epidemic dissemination.