Article detail · 2016
Update or wait: How to keep your data fresh
- Year
- 2016
- Type
- conference-paper
Abstract
OpenAlex · English
In this work we study how to manage the freshness of status updates sent from a source to a remote monitor via a network server. A proper metric of data freshness at the monitor is the age-of-information, which is defined as how old the freshest update is since the moment this update was generated at the source. A logical policy is the zero-wait policy, i.e., the source submits a fresh update once the server is free, which achieves the maximum throughput and the minimum average delay. Surprisingly, this zero-wait policy does not always minimize the average age. This motivates us to study how to optimally control the status updates to keep data fresh and to understand when the zero-wait policy is optimal. We introduce a penalty function to characterize the level of “dissatisfaction” on data staleness, and formulate the average age penalty minimization problem as a constrained semi-Markov decision process (SMDP) with an uncountable state space. Despite of the difficulty of this problem, we develop efficient algorithms to find the optimal status update policy. We show that, in many scenarios, the optimal policy is to wait for a certain amount of time before submitting a new update. In particular, the zero-wait policy can be far from the optimum if (i) the penalty function grows quickly with respect to the age, and (ii) the update service times are highly random and positive correlated. To the best of our knowledge, this is the first optimal control policy which is proven to minimize the age-of-information in status update systems.
Topics
Citations
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225 citations
OpenAlex cited_by_count (cache / database)
15 publications in the local catalog that cite this work (OpenAlex reference match; not the full global list).
- Update or Wait: How to Keep Your Data Fresh 2017
- Minimizing the Age of Information in broadcast wireless networks 2016
- Sampling of the Wiener Process for Remote Estimation Over a Channel With Random Delay 2019
- Remote estimation of the Wiener process over a channel with random delay 2017
- Age-optimal updates of multiple information flows 2018
- Optimizing age of information on real-life TCP/IP connections through reinforcement learning 2018
- Age-of-Information in Practice: Status Age Measured Over TCP/IP Connections Through WiFi, Ethernet and LTE 2018
- Scheduling status updates to minimize age of information with an energy harvesting sensor 2017
- A Reinforcement Learning Approach to Age of Information in Multi-User Networks With HARQ 2021
- A Reinforcement Learning Approach to Age of Information in Multi-User Networks With HARQ 2021