On the impact of graph structure on mobility in opportunistic mobile networks

Christoph P. Mayer, Oliver P. Waldhorst
2011 2011 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS)  
Opportunistic mobile networks are a promising way to offload infrastructure networks, or provide communication in case of insufficient or non-existent infrastructure coverage. Understanding of the mobility process that drives such networks is crucial for design, analysis, and configuration. Generally, this mobility process is modeled on a plain playground where devices can move freely; both in case of simulation, and analysis of real-world traces. Graph-based playgrounds provide more realistic
more » ... odels but their impact on mobility is insufficiently understood. We provide a methodology to analyze the impact of the underlying graph on inter-contact time using methods from spectral graph theory. We gather the inter-contact times that both a random and a social mobility model exhibit on synthetic grid-based graphs and real-world city maps through simulations and perform fitting to a model for inter-contact time distribution. We then analyze correlations between parameters of these distributions and the spectral gap of a graph. Our main finding is that the graph structure has strong impact on intercontact time distribution in both random and social mobility on grid-based graphs. For real-world city graphs a social mobility model determines inter-contact time independently of the graph structure, whereas the graph structure has strong impact on inter-contact times for a random mobility process.
doi:10.1109/infcomw.2011.5928937 fatcat:dvajnla2zzbj3lidqxxesrwrua