Mobility modeling in third-generation mobile telecommunications systems

In mobile communications, mobility modeling is involved in several aspects related to signaling and traffic load analysis. In third-generation systems, the influence of mobility on the network performance (e.g., handover rate) will be strengthened, mainly due to the huge number of mobile users in conjunction with the small cell size. In particular, the accuracy of mobility models becomes essential for the evaluation of system design alternatives and network implementation cost issues. In this article the authors propose three basic types of mobility models, which are appropriate for the analysis of the full range of mobile communications' design issues. The models provide different levels of detail regarding the user mobility behavior. In particular, a) the City Area Model traces user motion at an area zone level, b) the Area Zone Model considers users moving on a street network, and c) the Street Unit Model tracks user motion with an accuracy of a few meters. The validity of the basic models for mobile communications design aspects is highlighted. Moreover, an ''integrated mobility modeling tool'' which considers the basic mobility models as components is proposed, aiming at the development of a refined modeling approach. This is achieved by improving the accuracy of the input parameters of each basic model via the exchange of some specific (mobility-related) parameters among the component models. To justify the applicability of the proposed integrated tool for both the analysis of design aspects and network planning, indicative results are presented, derived from simulation-based application examples of the three basic mobility models.