Optimizing Information Freshness in Wireless Networks under General Interference Constraints

TL;DR

This paper studies how to minimize the freshness of information in wireless networks with interference constraints, proposing optimal scheduling policies and analyzing AoI in queue models.

Contribution

It introduces a stationary scheduling policy for peak AoI optimality and establishes a separation principle for joint scheduling and packet generation control.

Findings

Stationary policy is peak age optimal under constant information availability.

The proposed policy achieves average AoI within a factor of two of the optimal.

First analysis of AoI in discrete time G/Ber/1 queues.

Abstract

Age of information (AoI) is a recently proposed metric for measuring information freshness. AoI measures the time that elapsed since the last received update was generated. We consider the problem of minimizing average and peak AoI in a wireless networks, consisting of a set of source-destination links, under general interference constraints. When fresh information is always available for transmission, we show that a stationary scheduling policy is peak age optimal. We also prove that this policy achieves average age that is within a factor of two of the optimal average age. In the case where fresh information is not always available, and packet/information generation rate has to be controlled along with scheduling links for transmission, we prove an important separation principle: the optimal scheduling policy can be designed assuming fresh information, and independently, the packet generation rate control can be done by ignoring interference. Peak and average AoI for discrete time G/Ber/1 queue is analyzed for the first time, which may be of independent interest.