  Most existing works on transportation dynamics focus on networks of a fixed
structure, but networks whose nodes are mobile have become widespread, such as
cell-phone networks. We introduce a model to explore the basic physics of
transportation on mobile networks. Of particular interest are the dependence of
the throughput on the speed of agent movement and communication range. Our
computations reveal a hierarchical dependence for the former while, for the
latter, we find an algebraic power law between the throughput and the
communication range with an exponent determined by the speed. We develop a
physical theory based on the Fokker-Planck equation to explain these phenomena.
Our findings provide insights into complex transportation dynamics arising
commonly in natural and engineering systems.
