Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Error Control Coding in Low-Power Wireless Sensor Networks: When Is ECC Energy-Efficient? | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 74812 Pages 1-14 DOI WCN 2006 74812 Error Control Coding in Low-Power Wireless Sensor Networks When Is ECC Energy-Efficient Sheryl L. Howard Christian Schlegel and Kris Iniewski Department of Electrical Computer Engineering University of Alberta Edmonton AB Canada T6G 2V4 Received 31 October 2005 Revised 10 March 2006 Accepted 21 March 2006 This paper examines error control coding ECC use in wireless sensor networks WSNs to determine the energy efficiency of specific ECC implementations in WSNs. ECC provides coding gain resulting in transmitter energy savings at the cost of added decoder power consumption. This paper derives an expression for the critical distance dCR the distance at which the decoder s energy consumption per bit equals the transmit energy savings per bit due to coding gain compared to an uncoded system. Results for several decoder implementations both analog and digital are presented for dCR in different environments over a wide frequency range. In free space dCR is very large at lower frequencies suitable only for widely spaced outdoor sensors. In crowded environments and office buildings dCR drops significantly to 3 m or greater at 10 GHz. Interference is not considered it would lower dCR. Analog decoders are shown to be the most energy-efficient decoders in this study. Copyright 2006 Sheryl L. Howard et al. 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. 1. INTRODUCTION Wireless sensor networks are currently being considered for many communications applications including industrial security surveillance medical environment and weather monitoring among others. Due to limited embedded battery lifetime at each sensor node minimizing power consumption in the sensors and
