A Study of Mobility in Ad Hoc Networks and Its Effects on a Hop Count Based Distance Estimation

Hop Count based distance estimation is an important element for the distributed computation of coordinates in GPS free environments. Deriving a distance estimate from hop counts is prone to error especially when the algorithm is applied to a network of mobile devices. We define and analyze two error models to describe the origin of underestimated and overestimated distances in a mobile ad hoc network. Different movement patterns are examined to get an understanding of their impact on the length of one hop and, thus, the estimated distance. Our experiments and analysis indicate that mobility can have a positive effect on the accuracy of a distance estimate by an emerging effect of asynchronous computation and fluctuating distribution of nodes. In addition, we identify parameters, such as direction and variance in movements,that are responsible for the different influences of the presented mobility models.