LAUSR

In this paper, we present a mathematical framework to evaluate the performance of a typical outdoor user in an urban two-tier mobile network under a biased user association. The urban environment is abstracted by a Boolean scheme of blockages, which affects the deployment of outdoor base stations (BSs) and indoor small cell BSs, and the signal propagation characteristics of the wireless channels. A building is served by an indoor small cell BS with a certain probability, which we denote as occupation probability. Employing tools from stochastic geometry, we derive mathematical expressions for the coverage probability and the average spectral efficiency of a typical outdoor user. Numerical evaluations are carried out with the third generation partnership project compliant outdoor BS scenarios. Our results show that the increasing blockage density has a negative impact on the spectral efficiency in sparse outdoor BSs scenarios, but it has a positive impact on the performance of the network in dense outdoor BSs scenarios. We build our analysis on several assumptions, which are verified by extensive Monte Carlo simulations.