ABSTRACT

We discuss file delivery issues for a new approach to inexpensive, high rate wireless data called Infostations. As opposed to ubiquitous coverage, infostations offer geographically intermittent coverage at high speed (1Mbps to 1Gbps) since data, as compared to voice, can often tolerate significant delay. The infostations paradigm flips the usual slow-radio/fast-network scenario upside down and offers intriguing new design problems for wireless data networks. Collectively, we at WINLAB believe that the infostations scenario, especially with the emergence of the World Wide Web as both a communications medium and defacto standard is one way to obtain low cost wireless data. And perhaps controversially, we offer arguments that currently proposed extensions to cellular systems (such as the coming Third Generation) will not be able to offer data as inexpensively. In this chapter we describe the infostations concept and then concentrate on issues above the physical layer. Specifically, we worry about delay bounds on information delivery for variety of simple user mobility scenarios and infostation geometries. We then provide heuristic algorithms which closely approach these bounds.