Optimal infostation deployment for spatio-temporal information dissemination

A growing number of applications require disseminating information around specific geographical areas within a limited valid time. For example, the store in the mall area expects to publish the time-limited sales promotion to all the potential clients in the nearby area, before the discount activity end. In this paper, we study the problem of deploying infostation for geographical information dissemination. It aims to achieve the desired dissemination ratio under the given time constraint and to minimize the infostation deployment cost. Inspired by several observations in recent studies on realistic mobility model, we build a mobility graph to reflect the statistical characteristic of users movement in a area. Based on this graph, we formulate the infostation deployment problem as an optimization problem. Then, we prove it is NP-hard by reducing it to the classical vertex cover problem and then develop a greedy heuristic algorithm DGREEDY with the polynomial time complexity. Extensive simulations based on the real human mobility traces have been carried out to show the efficacy of our approach.