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 On Connectivity Limits in Ad Hoc Networks with Beamforming Antennas | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 878419 15 pages doi 2009 878419 Research Article On Connectivity Limits in Ad Hoc Networks with Beamforming Antennas Moritz Kiese Christian Hartmann Julian Lamberty and Robert Vilzmann Institute of Communication Networks Technische Universitat Munchen Arcisstrafe 21 80290 Munchen Germany Correspondence should be addressed to Christian Hartmann hartmann@ Received 2 December 2008 Revised 10 June 2009 Accepted 19 August 2009 Recommended by Wolfgang Utschick Multihop wireless networks will play an important role in future communication networks. Beamforming antennas have shown great potential to improve the connectivity in these networks however only heuristic approaches exist to assess the benefits of this technology. Using the popular keyhole antenna model we formulate a Mixed Integer Program MIP capable of acquiring optimal antenna configurations for path probability with various auxiliary constraints node degree and k-connectivity. We employ a problem-specific large-scale optimization approach named column generation to be able to cope with realistic scenario sizes without sacrificing optimality. In a case study we show the feasibility of our optimization approach and demonstrate that smarter beamforming heuristics would still have plenty of room to improve the connectivity of such a network. Copyright 2009 Moritz Kiese 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 The concept of multihop wireless communication is steadily gaining importance and will be an integral part of future wireless heterogeneous networking architectures. In this paper we consider multihop ad hoc and sensor networks which operate without the help of any central entity in a distributed
