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  • Research Article
  • Open Access

Optimizing Transmission and Shutdown for Energy-Efficient Real-time Packet Scheduling in Clustered Ad Hoc Networks

  • 1, 2Email author,
  • 1, 2,
  • 1, 3,
  • 1, 2,
  • 1, 4,
  • 3 and
  • 1
EURASIP Journal on Wireless Communications and Networking20052005:617271

  • Received: 30 June 2004
  • Published:


Energy efficiency is imperative to enable the deployment of ad hoc networks. Conventional power management focuses independently on the physical or MAC layer and approaches differ depending on the abstraction level. At the physical layer, the fundamental tradeoff between transmission rate and energy is exploited, which leads to transmit as slow as possible. At MAC level, power reduction techniques aim to transmit as fast as possible to maximize the radios power-off interval. The two approaches seem conflicting and it is not obvious which one is the most appropriate. We propose a transmission strategy that optimally mixes both techniques in a multiuser context. We present a cross-layer solution considering the transceiver power characteristics, the varying system load, and the dynamic channel constraints. Based on this, we derive a low-complexity online scheduling algorithm. Results considering an -ary quadrature amplitude modulation radio show that for a range of scenarios a large power reduction is achieved, compared to the case where only scaling or shutdown is considered.


  • clustered ad hoc networks
  • energy efficiency
  • lazy scheduling
  • shutdown
  • schedule-based MAC

Authors’ Affiliations

1Wireless Research, IMEC, Leuven, 3001, Belgium
ESAT/INSYS, Katholieke Universiteit Leuven, Leuven, 3001, Belgium
Real-Time & Multimedia Systems Laboratory, Carnegie Mellon University, Pittsburgh, PA 15213, USA
INTEC, Universiteit Gent, Gent, 9000, Belgium


© Sofie Pollin et al. 2005

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.