Paper Summary: Whittle Index Scheduling for Age of Information in IoT Networks
Published:
This post summarizes our paper published at IEEE SmartIOT 2025:
A Novel Whittle Index-Based Scheduling for Age of Information Minimization in IoT Networks
Motivation
In IoT networks, keeping information fresh matters. A sensor reading that is 10 seconds old may be useless for real-time control. Age of Information (AoI) captures this freshness — it measures the time elapsed since the last successful update from a source.
The challenge: with many sensors and limited transmission slots, which sensors should you update at each time step to keep the overall network as fresh as possible?
Our Approach
We modeled this as a Restless Multi-Armed Bandit (RMAB) problem, where each sensor is an “arm” with an evolving AoI state. We derived a Whittle index policy — a lightweight, scalable scheduling rule that assigns a priority score to each sensor based on its current AoI.
Key contributions:
- Proved the indexability of the AoI bandit problem under our model
- Derived a closed-form Whittle index for efficient computation
- Demonstrated near-optimal performance through simulations
Results
Our Whittle index policy significantly outperformed baseline round-robin scheduling and came close to the optimal policy computed by dynamic programming — at a fraction of the computational cost.
Link
Full paper: IEEE SmartIOT 2025
This post is part of the Research series — plain-language summaries of my published work.