tailieunhanh - Báo cáo hóa học: " IEEE 802.11 Wireless LANs: Performance Analysis and Protocol Refinement"

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: IEEE Wireless LANs: Performance Analysis and Protocol Refinement | EURASIP Journal on Applied Signal Processing 2005 1 67-78 2005 Hindawi Publishing Corporation IEEE Wireless LANs Performance Analysis and Protocol Refinement P Chatzimisios Multimedia Communications Research Group School of Design Engineering and Computing Bournemouth University Fern Barrow Poole Dorset BH12 5BB UK Email pchatzimisios@ A. C. Boucouvalas Multimedia Communications Research Group School of Design Engineering and Computing Bournemouth University Fern Barrow Poole Dorset BH12 5BB UK Email tboucouv@ V. Vitsas Information Technology Department Technological Educational Institute of Thessaloniki 54101 Thessaloniki Greece Email vitsas@ Received 25 February 2004 Revised 1 November 2004 Recommended for Publication by C. C. Ko The IEEE protocol is emerging as a widely used standard and has become the most mature technology for wireless local area networks WLANs . In this paper we focus on the tuning of the IEEE protocol parameters taking into consideration in addition to throughput efficiency performance metrics such as the average packet delay the probability of a packet being discarded when it reaches the maximum retransmission limit the average time to drop a packet and the packet interarrival time. We present an analysis which has been validated by simulation that is based on a Markov chain model commonly used in the literature. We further study the improvement on these performance metrics by employing suitable protocol parameters according to the specific communication needs of the IEEE protocol for both basic access and RTS CTS access schemes. We show that the use of a higher initial contention window size does not considerably degrade performance in small networks and performs significantly better in any other scenario. Moreover we conclude that the combination of a lower maximum contention window size and a higher retry limit considerably improves performance. Results indicate .