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 Admission Control and Interference Management in Dynamic Spectrum Access Networks | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2010 Article ID 708029 11 pages doi 2010 708029 Research Article Admission Control and Interference Management in Dynamic Spectrum Access Networks Jorge Martinez-Bauset Vicent Pla M. Jose Domenech-Benlloch and Diego Pacheco-Paramo Departamento de Comunicaciones Universidad Politécnica de Valencia UPV Camino de Vera s n 46022 Valencia Spain Correspondence should be addressed to Jorge Martinez-Bauset jmartinez@ Received 6 October 2009 Revised 16 February 2010 Accepted 9 May 2010 Academic Editor Gian Luigi Ferrari Copyright 2010 Jorge Martinez-Bauset 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. We study two important aspects to make dynamic spectrum access work in practice the admission policy of secondary users SUs to achieve a certain degree of quality of service and the management of the interference caused by SUs to primary users PUs . In order to limit the forced termination probability of SUs we evaluate the Fractional Guard Channel reservation scheme to give priority to spectrum handovers over new arrivals. We show that contrary to what has been proposed the throughput of SUs cannot be maximized by configuring the reservation parameter. We also study the interference caused by SUs to PUs. We propose and evaluate different mechanisms to reduce the interference which are based on simple spectrum access algorithms for both PUs and SUs and channel repacking algorithms for SUs. Numerical results show that the reduction can be of one order of magnitude or more with respect to the random access case. Finally we propose an adaptive admission control scheme that is able to limit simultaneously the forced termination probability of SUs and what we define as the probability of .
