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Báo cáo hóa học: " Research Article Channel MAC Protocol for Opportunistic Communication in Ad Hoc Wireless Networks'

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 Channel MAC Protocol for Opportunistic Communication in Ad Hoc Wireless Networks | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 368209 17 pages doi 10.1155 2009 368209 Research Article Channel MAC Protocol for Opportunistic Communication in Ad Hoc Wireless Networks Manzur Ashraf Aruna Jayasuriya and Sylvie Perreau Institute for Telecommunications Research University of South Australia Mawson Lakes Boulevard Mawson Lakes SA 5095 Australia Correspondence should be addressed to Manzur Ashraf manzur.ashraf@postgrads.unisa.edu.au Received 18 January 2008 Revised 12 June 2008 Accepted 28 July 2008 Recommended by S. Toumpis Despite significant research effort the performance of distributed medium access control methods has failed to meet theoretical expectations. This paper proposes a protocol named Channel MAC performing a fully distributed medium access control based on opportunistic communication principles. In this protocol nodes access the channel when the channel quality increases beyond a threshold while neighbouring nodes are deemed to be silent. Once a node starts transmitting it will keep transmitting until the channel becomes bad. We derive an analytical throughput limit for Channel MAC in a shared multiple access environment. Furthermore three performance metrics of Channel MAC throughput fairness and delay are analysed in single hop and multihop scenarios using NS2 simulations. The simulation results show throughput performance improvement of up to 130 with Channel MAC over IEEE 802.11. We also show that the severe resource starvation problem unfairness of IEEE 802.11 in some network scenarios is reduced by the Channel MAC mechanism. Copyright 2009 Manzur Ashraf 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 An ad hoc wireless network is a collection of wireless mobile nodes that self-configure to .