When to Preprocess? Keeping Information Fresh for Computing Enable Internet of Things

Age of information (AoI), a notion that measures the freshness, is an essential performance measure for time-critical applications in Internet Things (IoT). With surge computing resources at IoT devices, it possible to preprocess packets contain status update before sending them destination so as alleviate transmission burden. However, additional time and energy expenditure induced by also make optimal updating non-trivial problem. In this paper, we consider system, where device capable preprocessing transmission. Particularly, aim jointly design weighted sum average AoI consumption minimized. Due heterogeneity computation capacities, durations distinct actions are non-uniform. Therefore, formulate problem infinite horizon cost semi-Markov decision process (SMDP) then transform into discrete-time Markov process. We demonstrate policy threshold type with respect AoI. Equipped this, structure-aware relative iteration algorithm proposed obtain SMDP. Our analysis shows more beneficial regimes high AoIs, given can reduce required updates. further prove switching structure special scenario, updates transmitted over reliable channel, derive threshold. Finally, simulation results efficacy show outperforms two baseline policies.