Age Optimal Information Gathering and Dissemination on Graphs

Abstract

We consider the problem of timely exchange of updates between a central station and a set of ground terminals V , via a mobile agent that traverses across the ground terminals along a mobility graph G = (V, E). We design the trajectory of the mobile agent to minimize peak and average age of information (AoI), two newly proposed metrics for measuring timeliness of information. We consider randomized trajectories, in which the mobile agent travels from terminal i to terminal j with probability Pi,j. For the information gathering problem, we show that a randomized trajectory is peak age optimal and factor-8H average age optimal, where H is the mixing time of the randomized trajectory on the mobility graph G. We also show that the average age minimization problem is NP-hard. For the information dissemination problem, we prove that the same randomized trajectory is factor-O(H) peak and average age optimal. Moreover, we propose an age-based trajectory, which utilizes information about current age at terminals, and show that it is factor-2 average age optimal in a symmetric setting.The authors are with the

Towards Persistent Surveillance and Reconnaissance Using a Connected Swarm of Multiple UAVs

“…We examine the effectiveness of our algorithm using another measure of the timeliness of information called peak age of information (peak AoI) [22]. The peak AoI is defined as the worst-case age of information at target cell i, denoted as A p i .…”

“…Since newness of data is critical to support real-time services or surveillance, it has been investigated in various fields. The problem in the fields of data analytics, knowledge discovery, and control systems has been investigated under the names of timeliness [18], [19] and the Age of Information (AoI) [20]- [22]. These approaches have measured the newness of data in terms of the elapsed time since an initial data collection or an update on the data has occurred.…”

“…A concept known as the Age of Information has recently been employed to represent the freshness of the data in communication systems [20]- [22]. More closely related to our work involving UAVs, some researchers have solved the problem of collecting data from sensor nodes only once by generating two different trajectories for a single UAV, based on two different optimization metrics of the maximum AoI and the average AoI.…”

Minimizing Age in Gateway Based Update Systems

“…Given our takeaways, we believe that there should be path plans where the UAV visits the monitor more frequently that lead to a smaller age. Finally, in [9] the authors consider information dissemination from ground terminals (sensors) to a central terminal (monitor) using a mobile agent. However, communication between the mobile agent and the terminal is instantaneous.…”

Straggling for Covert Message Passing on Complete Graphs

“…Information gathering and dissemination on graphs is a very interesting problem that arises naturally and has recently seen active research in many different contexts. Examples include: border control using UAVs [4], measuring traffic, reporting road conditions and helping with emergency response using UAVs [5], monitoring the ocean [6], measuring air pollution [7], and more recently for timely exchange of information updates [8].…”