On the Performance of Pedestrian Content Distribution

Abstract

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.