On temporal variations in mobile user SNR with applications to perceived QoS
Pranav Madadi, François Baccelli, Gustavo de Veciana · 2016
This paper proposes a stochastic geometry framework to study the temporal performance variations experienced by a mobile user in a cellular network. The focus is on the variations of the Signal to Noise Ratio (SNR) and the downlink Shannon rate experienced when the user moves across Poisson cellular network of the Euclidean plane. The motion is the simplest possible i.e., a user moving at a constant velocity on a straight line. The level crossings of the associated SNR process are shown to form an alternating-renewal process. The two distributions characterizing this process are derived in closed form. The theory of rare events provides simplified expressions for the law of this process for extremes (very large and very small) SNR thresholds. The framework is then leveraged to predict the quality of service experienced by mobile users in two concrete scenarios: that of streaming a video on the downlink and partially buffered on the hand-set to prevent video freezing; and that of downloading a large file, where the main question is the download delay. Finally, discrete event simulation is used to assess practical use of this model on its robustness to perturbations that cannot presently be taken into account in the analysis.