Age of Aggregated Information- Minimizing Scheduling in Wireless Relay Network

Age of Information (AoI), as an emerging metric of data freshness, is defined as the time elapsed since the last received update was generated. To measure the age of aggregated information, we extend a metric from AoI in a wireless relay network, the Age of Aggregated Information, AoAI. AoAI is defined as the elapsed time since the last aggregated information was generated by source nodes. In this model, the destination node requests aggregated information from multiple source nodes. We propose a scheduling model to minimize the AoAI with the assistance of relay nodes, and formulate the problem as an Integer Linear Programming (ILP). Next, we propose a solution by using Column Generation Algorithm (CGA) and Rounding Algorithm (RA) to solve the problem. According to the performance evaluation results, we conclude that the proposed scheduling algorithm with relay nodes assistance outperforms existing node assistance agnostic scheme by 37.3% in terms of AoAI. And our proposed CGA-based algorithm achieves a very close AoAI (the average optimality gap is 5.897%) in comparison with ILP solution.