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 QoS Differentiated and Fair Packet Scheduling in Broadband Wireless Access Networks | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 482764 12 pages doi 2009 482764 Research Article QoS Differentiated and Fair Packet Scheduling in Broadband Wireless Access Networks Rong Yu 1 Yan Zhang 2 and Shengli Xie1 1 School of Electronic and Information Engineering South China University of Technology Guangzhou 510641 China 2 Simula Research Laboratory 1325 Lysaker Norway Correspondence should be addressed to Rong Yu yurong@ Received 12 February 2009 Accepted 7 September 2009 Recommended by Thomas Michael Bohnert This paper studies the packet scheduling problem in Broadband Wireless Access BWA networks. The key difficulties of the BWA scheduling problem lie in the high variability of wireless channel capacity and the unknown model of packet arrival process. It is difficult for traditional heuristic scheduling algorithms to handle the situation and guarantee satisfying performance in BWA networks. In this paper we introduce learning-based approach for a better solution. Specifically we formulate the packet scheduling problem as an average cost Semi-Markov Decision Process SMDP . Then we solve the SMDP by using reinforcement learning. A feature-based linear approximation and the Temporal-Difference learning technique are employed to produce a near optimal solution of the corresponding SMDP problem. The proposed algorithm called Reinforcement Learning Scheduling RLS has in-built capability of self-training. It is able to adaptively and timely regulate its scheduling policy according to the instantaneous network conditions. Simulation results indicate that RLS outperforms two classical scheduling algorithms and simultaneously considers i effective QoS differentiation ii high bandwidth utilization and iii both short-term and longterm fairness. Copyright 2009 Rong Yu et al. This is an open access article distributed under the Creative Commons Attribution License which permits .
