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: Research Article Efficient MAC Protocols for Wireless Sensor Networks Endowed with Directive Antennas: A Cross-Layer Solution | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID37910 9 pages doi 2007 37910 Research Article Efficient MAC Protocols for Wireless Sensor Networks Endowed with Directive Antennas A Cross-Layer Solution Gianfranco Manes Romano Fantacci Francesco Chiti Michele Ciabatti Giovanni Collodi Davide Di Palma Ilaria Nelli and Antonio Manes Department of Electronics and Telecommunications University of Florence Via di S. Marta 3 50139 Firenze Italy Received 21 October 2006 Revised 21 March 2007 Accepted 11 May 2007 Recommended by Mischa Dohler This paper deals with a novel MAC layer protocol namely directive synchronous transmission asynchronous reception D-STAR able to space-time synchronize a wireless sensor network WSN . To this end D-STAR integrates directional antennas within the communications framework while taking into account both sleep active states according to a cross-layer design. After characterizing the D-STAR protocol in terms of functional characteristics the related performance is presented in terms of network lifetime gain setup latency and collision probability. It has shown a remarkable gain in terms of energy consumption reduction with respect to the basic approach endowed with omnidirectional antennas without increasing the signaling overhead nor affecting the setup latency. Copyright 2007 Gianfranco Manes 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 WSNs 1 have been attracting a great deal of scientific interest in the last decade making this approach an enabling technology for intelligent environments instrumenting. The deployment of networks comprised of tens up to hundreds of sensors currently represents an affordable solution to some challenging problems environmental
