We consider the problem of minimizing the energy needed for data fusion in a sensor network by varying the transmission times assigned to different sensor nodes. The optimal scheduling protocol is derived, based on which we develop a low-complexity inverse-log scheduling (ILS) algorithm that achieves near-optimal energy efficiency. To eliminate the communication over-head required by centralized scheduling protocols, we further derive a distributed inverse-log protocol that is applicable to networks with a large number of nodes. Focusing on large-scale networks with high total data rates, we analyze the energy consumption of the ILS. Our analysis reveals how its energy gain over traditional time-division multiple access depends on the channel and the data-length variations among different nodes.
Bibliographical noteFunding Information:
Paper approved by X. Wang, the Editor for Modulation, Detection, and Equalization of the IEEE Communications Society. Manuscript received July 12, 2004; revised December 9, 2004 and February 27, 2005. This work was prepared through collaborative participation in the Communications and Networks Consortium sponsored by the U.S. Army Research Laboratory under the Collaborative Technology Alliance Program, and was supported in part under Cooperative Agreement DAAD19-01-2-0011, and in part by the U.S. Department of Defense under Army Grant W911NF-95-1-0283. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. This paper was presented in part at the IEEE International Conference on Communications, Seoul, Korea, May 2005.
- Energy efficiency
- Fading channels
- Packet scheduling
- Power-delay tradeoff
- Wireless networks