Large deviations in relay-augmented wireless networks

TL;DR

This paper models relay-augmented wireless networks with mobile users and analyzes the probability of large deviations in quality of service, revealing exponential decay rates and potential symmetry-breaking in the system.

Contribution

It introduces a probabilistic framework for large deviations in relay-augmented wireless networks with mobile users, characterizing decay rates via entropy minimization.

Findings

Probability of many users experiencing poor service decays exponentially.

Solutions to the entropy minimization problem may be non-unique due to symmetry breaking.

Two main causes of bad quality of service identified: isolation and screening.

Abstract

We analyze a model of relay-augmented cellular wireless networks. The network users, who move according to a general mobility model based on a Poisson point process of continuous trajectories in a bounded domain, try to communicate with a base station located at the origin. Messages can be sent either directly or indirectly by relaying over a second user. We show that in a scenario of an increasing number of users, the probability that an atypically high number of users experiences bad quality of service over a certain amount of time, decays at an exponential speed. This speed is characterized via a constrained entropy minimization problem. Further, we provide simulation results indicating that solutions of this problem are potentially non-unique due to symmetry breaking. Also two general sources for bad quality of service can be detected, which we refer to as isolation and screening.