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OPTIMIZING DATA FRESHNESS IN INFORMATION UPDATE SYSTEMS

Bedewy, Ahmed M
http://rave.ohiolink.edu/etdc/view?acc_num=osu1618573325086709

Abstract Details

2021, Doctor of Philosophy, Ohio State University, Electrical and Computer Engineering.
In applications such as networked monitoring and control systems, wireless sensor networks, and autonomous vehicles, it is crucial for the destination node to receive timely status updates so that it can make accurate decisions. For example, a moving car with a speed of 65 mph will traverse almost 29 meters in 1 second, and hence, stale information (regarding the location of surrounding vehicles, velocities, etc.) has a dramatic serious impact on this situation. Age of information (AoI), or simply age, has been used to measure the freshness of status updates. More specifically, AoI is the age of the freshest update at the destination, i.e., it is the time elapsed since the freshest received update was generated. It should be noted that optimizing traditional network performance metrics, such as throughput or delay, does not attain the goal of timely updating. For instance, it is well known that AoI could become very large when the offered load is high or low. In other words, AoI captures the information lag at the destination, and is hence more apt for achieving the goal of timely updates. In this thesis, we leverage rigorous theory to develop low-complexity scheduling algorithms that are apt for a wide range of information update systems. In particular, we consider the following systems: -Information update systems with stochastic packet arrivals: We consider single and multihop networks with stochastic arrivals, where our goal is to answer the following fundamental questions: (i) Which queueing discipline can minimize the age? And (ii) under what conditions is the minimum age achievable? Towards this goal, we design low-complexity scheduling policies to achieve (near) age-optimality in single and multihop networks with single source. The achieved results that we present here hold under quite general conditions, including (i) arbitrary packet generation and arrival processes, (ii) for minimizing both the age processes in stochastic ordering and any non-decreasing functional of the age processes, (iii) multi-server, single-hop networks with packet replications, and (iv) general multihop network topology. -Information update systems with controlled packet generation: We consider multi-source systems, where sources can control the generation of the update packets. Our goal is to address the following information update systems: (i) We consider the system in which sources take turns to generate update packets, and forward them to their destinations one-by-one through a shared channel with random delay. There is a scheduler, that chooses the update order of the sources, and a sampler, that determines when a source should generate a new sample in its turn. We aim to solve a challenging joint sampling and scheduling optimization problem for minimizing AoI. Although the complexity that is usually inherited in joint optimization problems, we are able to develop low-complexity optimal scheduler-sampler pairs that minimize AoI, (ii) since many information update devices are battery limited, scheduling policies that prolong the battery-lifetime sometimes are just as crucial as those that ensure information freshness. Towards that end, we consider the problem of optimizing the freshness of status updates that are sent from a large number of low-power sources to a common access point. We develop asynchronized sleep-wake scheduling algorithm that minimizes AoI, subject to per-source battery lifetime constraints. Although the problem turns out to be non-convex, we devise a low-complexity near-optimal solution.
Ness Shroff (Advisor)
Yin Sun (Other)
Atilla Eryilmaz (Committee Member)
Abhishek Gupta (Committee Member)
Qin Ma (Committee Member)
250 p.
Communication; Computer Engineering; Electrical Engineering
Age of information, data freshness, age-optimal, single hop network, multiple servers, packet replication, multihop network, sampler, scheduler, multi-source network, low-power, status update

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Citations

  • Bedewy, A. M. (2021). OPTIMIZING DATA FRESHNESS IN INFORMATION UPDATE SYSTEMS [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1618573325086709

    APA Style (7th edition)

  • Bedewy, Ahmed. OPTIMIZING DATA FRESHNESS IN INFORMATION UPDATE SYSTEMS. 2021. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1618573325086709.

    MLA Style (8th edition)

  • Bedewy, Ahmed. "OPTIMIZING DATA FRESHNESS IN INFORMATION UPDATE SYSTEMS." Doctoral dissertation, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1618573325086709

    Chicago Manual of Style (17th edition)

osu1618573325086709
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This open access ETD is published by The Ohio State University and OhioLINK.