Query Age of Information: Freshness in Pull-Based Communication

Age of Information (AoI) has become an important concept in communications, as it allows system designers to measure the freshness information available remote monitoring or control processes. However, its definition tacitly assumes that new is used at any time, which not always case: instants collected and may be dependent on a certain query process, resource-constrained environments such most Internet Things (IoT) use cases require precise timing fully exploit limited transmissions. In this work, we consider pull-based communication model only when receiver generates query: if process using value, age last update irrelevant. We optimize Query (QAoI), metric samples AoI relevant instants, better fitting pull-based scenario, show how can lead very different choices. Our results QAoI-aware optimization significantly reduce average worst-case perceived for both periodic stochastic queries.