Achieving AoI Fairness in Spatially Distributed Wireless Networks: From Theory to Implementation

Abstract: We design and implement two variants of a practical random access protocol called WiFair, based on IEEE 802.11 and designed to mitigate spatial unfairness in Age of Information (AoI). Drawing on previous theoretical work, we modify the mechanics of 802.11 to fairly minimize AoI in a wireless network consisting of several update nodes and a single base station. We implement this protocol on a testbed of software defined radios (SDRs) and measure its performance under a variety of settings compared to standard 802.11. We observe a 32% reduction in network average AoI and an 89% reduction in peak AoI in a last come first served (LCFS) single-packet queue setting, as well as a 76% reduction in network average AoI and an 82% reduction in peak AoI in a first come first served (FCFS) queue setting when the network is congested. We further show that when the network is uncongested, WiFair achieves the same performance as 802.11, and we demonstrate its robustness to more bursty traffic by streaming live video.