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Báo cáo hóa học: " Research Article Cross Layer PHY-MAC Protocol for Wireless Static and Mobile Ad Hoc 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 Cross Layer PHY-MAC Protocol for Wireless Static and Mobile Ad Hoc Networks | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 278041 13 pages doi 10.1155 2009 278041 Research Article Cross Layer PHY-MAC Protocol for Wireless Static and Mobile Ad Hoc Networks Sylwia Romaszko and Chris Blondia Interdisciplinary Institute for Broadband Technology University of Antwerp Middelheimlaan 1 2020 Antwerp Belgium Correspondence should be addressed to Sylwia Romaszko sylwia.romaszko@ua.ac.be Received 31 January 2008 Revised 5 June 2008 Accepted 26 July 2008 Recommended by S. Toumpis Multihop mobile wireless networks have drawn a lot of attention in recent years thanks to their wide applicability in civil and military environments. Since the existing IEEE 802.11 distributed coordination function DCF standard does not provide satisfactory access to the wireless medium in multihop mobile networks we have designed a cross-layer protocol CroSs-layer noise aware power driven MAC SNAPdMac which consists of two parts. The protocol first concentrates on the flexible adjustment of the upper and lower bounds of the contention window CW to lower the number of collisions. In addition it uses a power control scheme triggered by the medium access control MAC layer to limit the waste of energy and also to decrease the number of collisions. Thanks to a noticeable energy conservation and decrease of the number of collisions it prolongs significantly the lifetime of the network and delays the death of the first node while increasing both the throughput performance and the sending bit rate throughput fairness among contending flows. Copyright 2009 S. Romaszko and C. Blondia. This is an open access article distributed underthe Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction and Problem Definition The IEEE 802.11 1 standard for wireless local area networks WLANs specifies as contention-based MAC .