Modeling the Roaming in Large-scale Wireless Networks using Real Measurements

Campus wireless LANs (WLANs) are complex systems with hundreds of access points (APs) and thousands of users. To analyze the performance of wireless networking protocols, researchers need to construct simulations and testbed experiments that reproduce the characteristics of these networks. However, the generation of realistic models and benchmarks is challenging and there is only a limited set of models of roaming and access based on real measurement data. The main contribution of this paper is the modeling of the roaming activity. Specifically, we employed graph theory, modelled the roaming activity as a graph and measured its properties (e.g., diameter, degree of connectivity, connected components). For example, the negative binomial distribution models well the degree of connectivity. Furthermore, we analyzed the evolution of the roaming activity in the spatial and temporal domain and its impact on the properties of the graph.