Age-optimal information updates in multihop networks
Ahmed M. Bedewy,Yin Sun,Ness B. Shroff +2 more
- pp 576-580
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TLDR
In this paper, it was shown that a preemptive Last Generated First Served (LGFS) policy results in smaller age processes at all nodes of the network (in a stochastic ordering sense) than any other causal policy.Abstract:
The problem of reducing the age-of-information has been extensively studied in single-hop networks. In this paper, we minimize the age-of-information in general multihop networks. If the packet transmission times over the network links are exponentially distributed, we prove that a preemptive Last Generated First Served (LGFS) policy results in smaller age processes at all nodes of the network (in a stochastic ordering sense) than any other causal policy. In addition, for arbitrary distributions of packet transmission times, the non-preemptive LGFS policy is shown to minimize the age processes at all nodes among all non-preemptive work-conserving policies (again in a stochastic ordering sense). It is surprising that such simple policies can achieve optimality of the joint distribution of the age processes at all nodes even under arbitrary network topologies, as well as arbitrary packet generation and arrival times. These optimality results not only hold for the age processes, but also for any non-decreasing functional of the age processes.read more
Citations
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Journal ArticleDOI
Update or Wait: How to Keep Your Data Fresh
TL;DR: In this paper, the authors study how to optimally manage the freshness of information updates sent from a source node to a destination via a channel and develop efficient algorithms to find the optimal update policy among all causal policies and establish sufficient and necessary conditions for the optimality of the zero-wait policy.
Journal ArticleDOI
The Age of Information: Real-Time Status Updating by Multiple Sources
Roy D. Yates,Sanjit K. Kaul +1 more
TL;DR: An age of information timeliness metric is formulated and a general result for the AoI that is applicable to a wide variety of multiple source service systems is derived that makes AoI evaluation to be comparable in complexity to finding the stationary distribution of a finite-state Markov chain.
Book
Age of Information: A New Concept, Metric, and Tool
TL;DR: This monograph provides the reader with an easy-to-read tutorial-like introduction into this novel approach of dealing with information within systems and shows how the approach can be used as a tool in improving metrics in other contexts.
Journal ArticleDOI
Scheduling Policies for Minimizing Age of Information in Broadcast Wireless Networks
TL;DR: In this article, the authors consider a wireless broadcast network with a base station sending time-sensitive information to a number of clients through unreliable channels and formulate a discrete-time decision problem to find a transmission scheduling policy that minimizes the expected weighted sum AoI of the clients in the network.
Posted Content
Age of Information: An Introduction and Survey
TL;DR: The current state of the art in the design and optimization of low-latency cyberphysical systems and applications in which sources send time-stamped status updates to interested recipients is described and AoI timeliness metrics are described.
References
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Proceedings ArticleDOI
Real-time status: How often should one update?
TL;DR: A time-average age metric is employed for the performance evaluation of status update systems and the existence of an optimal rate at which a source must generate its information to keep its status as timely as possible at all its monitors is shown.
Journal ArticleDOI
Update or Wait: How to Keep Your Data Fresh
TL;DR: In this paper, the authors study how to optimally manage the freshness of information updates sent from a source node to a destination via a channel and develop efficient algorithms to find the optimal update policy among all causal policies and establish sufficient and necessary conditions for the optimality of the zero-wait policy.
Proceedings ArticleDOI
Status updates through queues
TL;DR: A time-averaged age metric is employed for characterizing performance of status update systems in which sources send updates of their status to interested recipients to be as timely as possible; however, this is typically constrained by limited network resources.
Proceedings ArticleDOI
Lazy is timely: Status updates by an energy harvesting source
TL;DR: It is shown that an optimal policy is lazy; following a service completion, the service facility is frequently left idle even though the server may have sufficient energy to submit an update.
Journal ArticleDOI
Synchronizing a database to improve freshness
Junghoo Cho,Hector Garcia-Molina +1 more
TL;DR: This paper studies how to refresh a local copy of an autonomous data source to maintain the copy up-to-date, and defines two freshness metrics, change models of the underlying data, and synchronization policies.