How wireless queues benefit from motion: an analysis of the continuum between zero and infinite mobility

This paper considers the time evolution of a queue that is embedded in a Poisson point process of moving wireless interferers. The queue is driven by an external arrival process and is subject to a time-varying service process that is a function of the SINR that it sees. Static configurations of interferers result in an infinite queue workload with positive probability. In contrast, a generic stability condition is established for the queue in the case where interferers possess any non-zero mobility that results in displacements that are both independent across interferers and oblivious to interferer positions. The proof leverages the mixing property of the Poisson point process. The effect of an increase in mobility on queueing metrics is also studied. Convex ordering tools are used to establish that faster moving interferers result in a queue workload that is larger for the increasing convex stochastic order. As a corollary, mean workload and mean delay improve as network mobility increases. Positive correlation between SINR level-crossing events at different time points is established and the autocorrelation function is determined. System behaviour is empirically analyzed using discrete-event simulation. The performance of various mobility models is evaluated using heavy-traffic approximations.