Maximizing Energy Efficiency in Multiple Access Channels by Exploiting Packet Dropping and Transmitter Buffering

Abstract

Abstract-Quality of service (QoS) for a network is characterized in terms of various parameters specifying packet delay and loss tolerance requirements for the application. The unpredictable nature of the wireless channel demands for application of certain mechanisms to meet the QoS requirements. Traditionally, medium access control (MAC) and network layers perform these tasks. However, these mechanisms do not take (fading) channel conditions into account. In this paper, we investigate the problem using cross layer techniques where information flow and joint optimization of higher and physical layer is permitted. We propose a scheduling scheme to optimize the energy consumption of a multiuser multi-access system such that QoS constraints in terms of packet loss are fulfilled while the system is able to maximize the advantages emerging from multiuser diversity. Specifically, this work focuses on modeling and analyzing the effects of packet buffering capabilities of the transmitter on the system energy for a packet loss tolerant application. We discuss low complexity schemes which show comparable performance to the proposed scheme. The numerical evaluation reveals useful insights about the coupling effects of different QoS parameters on the system energy consumption and validates our analytical results.

Energy and Bursty Packet Loss Tradeoff Over Fading Channels: A System-Level Model

“…This work extends the work in [15] to the cases when CSI available at the transmitter and the receiver is not perfect, which logically translates into the problem of providing statistical guarantees on N to the individual users.…”

“…The works in references [14], [15] consider perfect channel state information (CSI) at both transmitter and receiver sides. The sequence of maximum number of packets allowed to be dropped successively for a given average packet drop rate θ tar is termed as continuity constraint (CCON) parameter and denoted by N .…”

“…The works in [12], [13] consider intentional packet dropping mechanisms for delay limited systems to minimize energy consumption over fading channels. Some recent works in [14], [15] consider data loss tolerance as an other aspect of the system which can be exploited to save system energy. The authors in [14] introduce a framework to achieve energy efficiency in a multiuser multiple access system for an application with average packet loss and maximum successive packet loss constraint.…”

“…The authors in [14] introduce a framework to achieve energy efficiency in a multiuser multiple access system for an application with average packet loss and maximum successive packet loss constraint. This work is generalized to a system with a finite buffer size in [15] and it analyzes the bounds on buffer size for the loss tolerance parameters.…”

“…complex Gaussian random variable with zero mean and unit variance. This work focuses on leveraging the analysis of the scheme proposed in [15] when perfect CSI is not available. Assumption of perfect CSI helps to perform system analysis and get insights about different trade-offs involved in system design.…”