Human Mobility Patterns and Their Impact on Delay Tolerant Networks

We conduct a statistical study of human mobility using over 1000 hours of GPS traces of human walks involving 44 participants in five different locations, two university campuses, state fair, New York City, and Disney World. Our data reveals statistical features similar to those in what physicists have long called Levy random walks (or Levy walks). These features include heavy-tail distributions of flight lengths and super-diffusive nature of mobility. We find that these tendencies are likely caused by human intentions in deciding travel destinations (and distance and sojourn time thereof), but not by geographical constraints such as roads, buildings, boundaries, etc, and that geographical constraints, instead, cause truncations of flight lengths and discontinuity in the statistical tendency of mobility statistics. Based on these findings, we construct a simple Levy walk mobility model that emulates human walk patterns expected in outdoor mobile networks carried by humans. Based on these findings, we construct a simple Levy walk mobility model that emulates human walk patterns expected in outdoor mobile network environments. We demonstrate that the Levy walk model can be used to recreate the statistical patterns commonly observed in previous mobility studies such as the power-law distributions of human inter-contact times and that the simulation performance of mobile network routing protocols under the Levy walk model exhibits distinctive performance features unexplored under existing mobility models.