Context-Aware Information Lapse for Timely Status Updates in Remote Control Systems

Abstract

As 5G and Internet-of-Things (IoT) are deeply integrated into vertical industries such as autonomous driving and industrial robotics, timely status update is crucial for remote monitoring and control. In this regard, Age of Information (AoI) has been proposed to measure the freshness of status updates.However, it is just a metric changing linearly with time and irrelevant of context-awareness. We propose a context-based metric, named as Urgency of Information (UoI), to measure the nonlinear time-varying importance and the non-uniform context-dependence of the status information. This paper first establishes a theoretical framework for UoI characterization and then provides UoI-optimal status updating and user scheduling schemes in both single-terminal and multi-terminal cases. Specifically, an update-indexbased scheme is proposed for a single-terminal system, where the terminal always updates and transmits when its update index is larger than a threshold. For the multi-terminal case, the UoI of the proposed scheduling scheme is proven to be upper-bounded and its decentralized implementation by Carrier Sensing Multiple Access with Collision Avoidance (CSMA/CA) is also provided. In the simulations, the proposed updating and scheduling schemes notably outperform the existing ones such as round robin and AoI-optimal schemes in terms of UoI, error-bound violation and control system stability. Index TermsRemote control systems, status update, transmission scheduling, Age-of-Information, 5G, Internet of Things.

Space-air-ground integrated vehicular network for connected and automated vehicles: Challenges and solutions

“…To this end, to measure the timeliness of status updates in remote control systems, we propose a new metric called the Urgency of Information (UoI) (previously the contextaware information lapse in Refs. [60,61]), which is defined as the product of weight !.t / and cost ı.Q.t //:…”

Cached Files Updating Revisited: The Distribution of Popularity-Weighted Average File Age

“…, n N ) should be included. We have different equations like (15) and (16) corresponding to every permutation of (n 1 , n 2 , . .…”

“…Under the discrete time model, many system design problems based on AoI are considered in recently years, such as [6][7][8][9][10][11][12][13][14][15][16]. A variety of optimization methods are used even combining with the machine learning [17][18][19][20][21][22][23].…”

Cached Files Updating Revisited: The Distribution of Popularity-Weighted Average File Age

“…In the following, we solve the system of equations (24) in Theorem 2 so that all the stationary probabilities can be found. In order to show the idea and solving method, we first consider the case N = 3.…”

“…In Theorem 3, for the case N = 3 we completely solve the stationary equations (24) and determine the stationary probability for each state vector. The detailed calculations are postponed to Appendix A.…”