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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: ZAP: a distributed channel assignment algorithm for cognitive radio networks | Junior et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 27 EURASIP Journal on . http jwcn.eurasipjournals.eom content 2011 1 27 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access ZAP a distributed channel assignment algorithm for cognitive radio networks Paulo Roberto Walenga Junior 1 Mauro Fonseca1 Anelise Munaretto2 Aline Carneiro Viana3 and Artur Ziviani4 Abstract We propose ZAP an algorithm for the distributed channel assignment in cognitive radio CR networks. CRs are capable of identifying underutilized licensed bands of the spectrum allowing their reuse by secondary users without interfering with primary users. In this context efficient channel assignment is challenging as ideally it must be simple incur acceptable communication overhead provide timely response and be adaptive to accommodate frequent changes in the network. Another challenge is the optimization of network capacity through interference minimization. In contrast to related work ZAP addresses these challenges with a fully distributed approach based only on local neighborhood knowledge while significantly reducing computational costs and the number of messages required for channel assignment. Simulations confirm the efficiency of ZAP in terms of i the performance tradeoff between different metrics and ii the fast achievement of a suitable assignment solution regardless of network size and density. Keywords Cognitive Radio Networks Wireless Networks Channel Selection Distributed Solution 1. Introduction The unlicensed portion of the spectrum becomes increasingly overloaded because of the growing number of wireless nodes and mobile users. While a small portion of the frequency spectrum is overloaded a large part of the frequency spectrum licensed to primary users is being underutilized or never used at all 1 . Cognitive radios CRs 2-4 allow the reuse of underutilized portions of the frequency spectrum by secondary users SUs in a .
