On the Performance of Pedestrian Content Distribution

Mobile communication devices may be used for spreading multimedia data without support of an infrastructure. Such a scheme, where the data is carried by people walking around and relayed from device to device by means of short range radio, could potentially form a public content distribution system that spans vast urban areas. There are basically only three system parameters that can be determined in the design: the transmission range of the nodes, the setup time when nodes make a contact, and their storage capacity. The transport mechanism is the flow of people and it can be studied but not engineered. The question addressed in this paper is how well pedestrian content distribution may work. We answer this question by modeling the mobility of people moving around in a city, constrained by a given topology. The model is supplemented by simulation of similar or related scenarios for validation and extension. Our conclusion is that contents spread well with pedestrian speeds already at low arrival rates into a studied region. Our contributions are both the results on the feasibility of pedestrian content distribution and the queuing analytic model that captures the flow of people.