Age of Information

The Age of Information (AoI) is a recently proposed performance metric that captures the freshness of information from the perspective of the destination in an communication network. Data scientists introduced the concept of Age of Information (AoI) as a data freshness metric in the early 1990s to evaluate data in terms of temporal consistency in real-time databases. With the fast progress of information technology, the concept of AoI extended to other study fields such as wireless communication, since timely information transmission became more essential for present wireless communication applications. Recent developments in AoI research reveal that several well-known design concepts of traditional data and communication networks (for example, maintaining high throughput and low latency) must be reconsidered in order to improve information freshness in real-time applications.

AoI Estimation

When the most recent received update of the destination at time ([math]\displaystyle{ t }[/math]) has the generating time-stamp ([math]\displaystyle{ a(t) }[/math]), the age ([math]\displaystyle{ \Delta (t) }[/math]) is determined by a random process as follows:

[math]\displaystyle{ \Delta (t)=t-a(t). }[/math]

For a updating system with [math]\displaystyle{ (Y) }[/math] as the interarrival time between given updates and [math]\displaystyle{ (X) }[/math] as the system time of such a delivered packet, the time-average AoI [math]\displaystyle{ (\Delta_{a}) }[/math] is given by

[math]\displaystyle{ \Delta_{a}=\frac{\frac{\mathbb{E}[X^{2}]}{2}+\mathbb{E}[XY]}{\mathbb{E}[X]} }[/math]

See also

• Network delay
• Latency (engineering)
• Interrupt latency
• Lead time
• Memory latency
• Performance engineering
• Response time (technology)
• Responsiveness
• End-to-end delay
• Minimum-Pairs Protocol
• Round-trip delay

 This article incorporates text from a free content work. Licensed under CC BY 4.0 Age of Information in an URLLC-enabled Decode-and-Forward Wireless Communication System, Chathuranga M. Wijerathna Basnayaka, Dushantha Nalin K. Jayakody, Tharindu D. Ponnimbaduge Perera, Moises Vidal Ribeiro, arXiv. To learn how to add open license text to HandWiki articles, please see this how-to page. For information on reusing text from HandWiki, please see the terms of use.