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

Nicholas Jones, Joshua Wornell, Chao Li, Eytan Modiano

TL;DR

This work designs and validates two practical AoI-aware random-access protocols, WiFair PF and WiFair TA, that modify IEEE 802.11 DCF to mitigate spatial unfairness in AoI across a spatially distributed network. Grounded in theory, the protocols compute node-specific contention windows from an AoI-centric optimization and map them to hardware via measured receive powers, enabling distributed, near-optimal AoI performance. Experiments on an SDR testbed show substantial reductions in average and especially peak AoI compared with standard 802.11, with near-identical performance in uncongested scenarios and robustness to bursty video traffic. The results demonstrate that spatial fairness in AoI can be achieved in practice with simple protocol adjustments, offering a path toward scalable, time-sensitive wireless networks.

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.

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

TL;DR

This work designs and validates two practical AoI-aware random-access protocols, WiFair PF and WiFair TA, that modify IEEE 802.11 DCF to mitigate spatial unfairness in AoI across a spatially distributed network. Grounded in theory, the protocols compute node-specific contention windows from an AoI-centric optimization and map them to hardware via measured receive powers, enabling distributed, near-optimal AoI performance. Experiments on an SDR testbed show substantial reductions in average and especially peak AoI compared with standard 802.11, with near-identical performance in uncongested scenarios and robustness to bursty video traffic. The results demonstrate that spatial fairness in AoI can be achieved in practice with simple protocol adjustments, offering a path toward scalable, time-sensitive wireless networks.

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.
Paper Structure (9 sections, 12 equations, 6 figures, 6 tables)

This paper contains 9 sections, 12 equations, 6 figures, 6 tables.

Table of Contents

  1. Introduction
  2. Theoretical Background
  3. Protocol Design
  4. Experimental Setup
  5. Experimental Results
  6. Single-Packet Queues
  7. FCFS Queues with Video Streams
  8. FCFS Queues with Congestion
  9. Conclusion

Figures (6)

  • Figure 1: AoI evolution over time
  • Figure 2: Experimental setup with seven transmitters and one receiver
  • Figure 3: AoI under WiFair vs 802.11 with single-packet LCFS queues
  • Figure 4: Received video screenshot under WiFair PF, WiFair TA, and 802.11 respectively
  • Figure 5: AoI under WiFair vs 802.11 with FCFS queues sending UDP video streams
  • ...and 1 more figures