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 A QoS-Based Dynamic Queue Length Scheduling Algorithm in Multiantenna Heterogeneous Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2010 Article ID 564527 10 pages doi 2010 564527 Research Article A QoS-Based Dynamic Queue Length Scheduling Algorithm in Multiantenna Heterogeneous Systems Nizar Zorba1 and Christos Verikoukis2 department of Electrical Engineering University of Jordan Amman 11942 Jordan 2Telecommunications Technological Center of Catalonia CTTC Barcelona 08860 Spain Correspondence should be addressed to Nizar Zorba Received 30 July 2009 Accepted 25 November 2009 Academic Editor Yevgeni Koucheryavy Copyright 2010 N. Zorba and C. Verikoukis. 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. The use of real-time delay-sensitive applications in wireless systems has significantly grown during the last years. Therefore the designers of wireless systems have faced a challenging issue to guarantee the required Quality of Service QoS . On the other hand the recent advances and the extensive use of multiple antennas have already been included in several commercial standards where the multibeam opportunistic transmission beamforming strategies have been proposed to improve the performance of the wireless systems. A cross-layer-based dynamically tuned queue length scheduler is presented in this paper for the Downlink of multiuser and multiantenna WLAN systems with heterogeneous traffic requirements. To align with modern wireless systems transmission strategies an opportunistic scheduling algorithm is employed while a priority to the different traffic classes is applied. A tradeoff between the maximization of the throughput of the system and the guarantee of the maximum allowed delay is obtained. Therefore the length of the queue is dynamically adjusted to select the appropriate conditions based on the operator .