Superdiffusive Behavior of Mobile Nodes and Its Impact on Routing Protocol Performance

Abstract

Abstract-Mobility is the most important component in mobile ad-hoc networks (MANETs) and delay-tolerant networks (DTNs).In this paper, we first investigate numerous GPS mobility traces of human mobile nodes and observe super-diffusive behavior in all GPS traces, which is characterized by a 'faster-than-linear' growth rate of the mean square displacement (MSD) of a mobile node. We then investigate a large amount of access point (AP) based traces, and develop a theoretical framework built upon continuous time random walk (CTRW) formalism, in which one can identify the degree of diffusive behavior of mobile nodes even under possibly heavy-tailed pause time distribution, as in the case of reality. We study existing synthetic models and trace based models in term of the capability of producing various degrees of diffusive behavior, and use a set of Lévy walk models due to its simplicity and flexibility. In addition, we show that diffusive properties make a huge impact on contact-based metrics and the performance of routing protocols in various scenarios and that existing models such as random waypoint, random direction model or Brownian motion lead to overly optimistic or pessimistic results when diffusive properties are not properly captured. Our work in this paper thus suggests that the diffusive behavior of mobile nodes should be correctly captured and taken into account for the design and comparison study of network protocols.

Online Gambling of Pure Chance: Wager Distribution, Risk Attitude, and Anomalous Diffusion

“…Within this paper, we will mainly focus on the analysis at the population level. Physicists have long been studying diffusion processes in different systems, and recently anomalous diffusive properties have been reported in many human activities, including human spatial movement [9][10][11] , and information foraging 12 . In a previous study of skin gambling 8 , we have shown that in a parimutuel betting game (where players gamble against each other), a gambler's net income displays a crossover from superdiffusion to normal diffusion.…”

Information dissemination in mobile networks

“…These values of γ produce super-diffusion patterns and can be modeled using Lévy walk processes -step lengths have infinite variance. Kim et al, (144) analyze several human GPS mobility traces showing super-diffusive behavior and its impact on contact-based metrics.…”