Coverage Dynamics: Modeling and Analysis of Data Coverage in Heterogeneous Edge Networks

Our study in the previous chapter revealed the lifetime of mobile data in large networks, to address the when question. In this chapter, we shift gear to another important aspect of mobile data, that is, the whereabouts of data in the space domain. Specifically, we study where data are accessible, i.e., data coverage during a data dissemination process. This question is of particular importance to location-based service (LBS), in which data are tagged with geographical positions, and disseminated though mobile devices with diverse capabilities in edge networks. However, existing research on data dissemination either do not carry the notation of ‘where’, or assume participants of the dissemination process to be homogeneous in communication, mobility, and other aspects. To overcome these challenges induced by the introduction of spatial domain and device heterogeneity, we propose a data coverage model that captures the attributes and actions of individual participants, and quantify the data coverage with a data strength metric, by which the dynamic change of data coverage can be described as a numeric signal on a graph that embeds location information. Analyzing this graph signal over entity mobility and data forwarding, we find that, the impact of entity mobility is high, especially when entities are less active in forwarding, or moving in low speed. Moreover, such impact acts in the form of a user mobility matrix, which indicates the underlying graph topology of the defined signal of data strength.