Smoothly truncated levy walks: Toward a realistic mobility model

Abstract

Mobility models are crucial for the simulation and evaluation of protocols for multihop wireless networks. However, most commonly used mobility models do not reflect the way humans actually move. This significantly affects the reliability of simulation results. In this paper we introduce a new mobility model called the Smoothly Truncated Levy Walk (STLW), which is more realistic than most standard models that appear in the literature. Its main innovations are as follows. First, to take into account dependencies in the direction of motion, it models changes in the direction instead of the standard approach, which directly models the direction and ignores these dependencies. Second, it uses realistic models for pause times, flight lengths, and changes in direction. In particular, it uses tempered stable distributions to model pause times and flight lengths and the beta distribution to model changes in direction. We justify the use of these distributions from both a theoretical and an empirical perspective. In particular, we perform a trace-based validation on several real-world traces from various scenarios. Validation results show that this model is very flexible and can be used to model human movements in a variety of situations.