Fundamentals of Mobility-Aware Performance Characterization of Cellular Networks: A Tutorial

This paper provides a tutorial on mobility-aware performance analysis of cellular networks considering both the spatially random [where base stations (BSs) are deployed according to a homogeneous point process] and deterministic grid-based network deployment topologies. We first provide a summary of users' mobility models with no spatiotemporal correlations (e.g., random walk, random way point, and random direction), with spatial correlations (e.g., pursue mobility and column mobility), and with temporal correlations (e.g., Gauss-Markov and Levy flight). The differences among various mobility models, their statistical properties, and their pros and cons are presented. We then describe two primary approaches (referred to as trajectory-based and association-based approaches) for mobility-aware performance analysis of both random and deterministic cellular networks. For the first approach (which is more general but less tractable than the other approach), we describe a general methodology and present several case studies for different cellular network tessellations, such as square lattice, hexagon lattice, single-tier, and multi-tier models in which BSs follow a homogeneous Poisson point process (PPP). For the second approach, we also outline the general methodology and highlight some limitations/imperfections of the existing techniques and provide corrections to these imperfections. For both of these approaches, we present selected numerical and simulation results to calibrate the achievable handoff rate and coverage probability in various network settings. Finally, we point out specific emerging fifth generation (5G) cellular wireless applications where the impact of mobility would be significant and outline the challenges associated with mobility-aware analysis of those network applications.