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Báo cáo hóa học: " Research Article Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks"

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 Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 21808 13 pages doi 10.1155 2007 21808 Research Article Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks Abraham O. Fapojuwo and Yinggan Huang Department of Electrical and Computer Engineering The University of Calgary 2500 University Drive NW Calgary Alberta Canada T2N1N4 Received 8 May 2007 Accepted 23 August 2007 Recommended by Sudip Misra We propose a two-level call admission control CAC scheme for direct sequence code division multiple access DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However to ensure some minimum level of performance for nonreal-time calls the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking outage probability throughput and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems. Copyright 2007 A. O. Fapojuwo and Y. Huang. This is an open access article distributed under the Creative Commons .