Synthesis Lectures on Communication Networks

2 total works

Age of Information

by Yin Sun, Igor Kadota, Rajat Talak, and Eytan Modiano

Published 11 December 2019

Information usually has the highest value when it is fresh.

For example, real-time knowledge about the location, orientation, and speed of motor vehicles is imperative in autonomous driving, and the access to timely information about stock prices and interest rate movements is essential for developing trading strategies on...Read more

Information usually has the highest value when it is fresh.

For example, real-time knowledge about the location, orientation, and speed of motor vehicles is imperative in autonomous driving, and the access to timely information about stock prices and interest rate movements is essential for developing trading strategies on the stock market. The Age of Information (AoI) concept, together with its recent extensions, provides a means of quantifying the freshness of information and an opportunity to improve the performance of real-time systems and networks. Recent research advances on AoI suggest that many well-known design principles of traditional data networks (for, e.g., providing high throughput and low delay) need to be re-examined for enhancing information freshness in rapidly emerging real-time applications.

This book provides a suite of analytical tools and insightful results on the generation of information-update packets at the source nodes and the design of network protocols forwarding the packets to their destinations. The book also points out interesting connections between AoI concept and information theory, signal processing, and control theory, which are worthy of future investigation.

Energy-Efficient Scheduling under Delay Constraints for Wireless Networks

by Randal Berry, Eytan Modiano, and Murtaza Zafer

Published 1 October 2012

Packet delay and energy consumption are important considerations in wireless and sensor networks as these metrics directly affect the quality of service of the application and the resource consumption of the network; especially, for a rapidly growing class of real-time applications that impose strict restrictions on packet delays. Dynamic...Read more

Packet delay and energy consumption are important considerations in wireless and sensor networks as these metrics directly affect the quality of service of the application and the resource consumption of the network; especially, for a rapidly growing class of real-time applications that impose strict restrictions on packet delays. Dynamic rate control is a novel technique for adapting the transmission rate of wireless devices, almost in real-time, to opportunistically exploit time-varying channel conditions as well as changing traffic patterns. Since power consumption is not a linear function of the rate and varies significantly with the channel conditions, adapting the rate has significant benefits in minimizing energy consumption. These benefits have prompted significant research in developing algorithms for achieving optimal rate adaptation while satisfying quality of service requirements. In this book, we provide a comprehensive study of dynamic rate control for energy minimization under packet delay constraints. We present several formulations and approaches adopted in the literature ranging from discrete-time formulations and dynamic programming based solutions to continuous-time approaches utilizing ideas from network calculus and stochastic optimal control theory. The goal of this book is to expose the reader to the important problem of wireless data transmission with delay constraints and to the rich set of tools developed in recent years to address it.