Energy Efficiency and Delay Quality-of-Service in Wireless Networks

TL;DR

This paper analyzes the energy-delay tradeoffs in wireless networks using game theory, providing insights into how delay-sensitive users impact energy efficiency and network capacity, with explicit equilibrium solutions and resource tradeoff quantifications.

Contribution

It introduces a game-theoretic framework for analyzing energy-delay tradeoffs, deriving closed-form equilibrium utilities, and quantifying the impact of delay constraints on network performance.

Findings

Nash equilibrium utilities are explicitly derived.

Delay-sensitive users reduce overall energy efficiency.

Tradeoffs among throughput, delay, capacity, and energy are quantified.

Abstract

The energy-delay tradeoffs in wireless networks are studied using a game-theoretic framework. A multi-class multiple-access network is considered in which users choose their transmit powers, and possibly transmission rates, in a distributed manner to maximize their own utilities while satisfying their delay quality-of-service (QoS) requirements. The utility function considered here measures the number of reliable bits transmitted per Joule of energy consumed and is particularly useful for energy-constrained networks. The Nash equilibrium solution for the proposed non-cooperative game is presented and closed-form expressions for the users' utilities at equilibrium are obtained. Based on this, the losses in energy efficiency and network capacity due to presence of delay-sensitive users are quantified. The analysis is extended to the scenario where the QoS requirements include both the average source rate and a bound on the average total delay (including queuing delay). It is shown that the incoming traffic rate and the delay constraint of a user translate into a "size" for the user, which is an indication of the amount of resources consumed by the user. Using this framework, the tradeoffs among throughput, delay, network capacity and energy efficiency are also quantified.