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: Traffic Agents for Improving QoS in Mixed Infrastructure and Ad Hoc Modes Wireless LAN | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 94235 Pages 1-7 DOI WCN 2006 94235 Traffic Agents for Improving QoS in Mixed Infrastructure and Ad Hoc Modes Wireless LAN Yang Yang 1 Hai-Feng Yuan 2 Hsiao-Hwa Chen 3 Wen-Bing Yao 2 and Yong-Hua Song2 1 Department of Electronic and Electrical Engineering University College London Gower Street London WC1E6BT UK 2 School of Engineering and Design Brunel University Uxbridge UB8 3PH UK 3 Institute of Communications Engineering National Sun Yat-Sen University Kaohsiung 804 Taiwan Received 12 July 2005 Revised 5 December 2005 Accepted 28 December 2005 As an important complement to infrastructured wireless networks mobile ad hoc networks MANET are more flexible in providing wireless access services but more difficult in meeting different quality of service QoS requirements for mobile customers. Both infrastructure and ad hoc network structures are supported in wireless local area networks WLAN which can offer high data-rate wireless multimedia services to the mobile stations MSs in a limited geographical area. For those out-of-coverage MSs how to effectively connect them to the access point AP and provide QoS support is a challenging issue. By mixing the infrastructure and the ad hoc modes in WLAN we propose in this paper a new coverage improvement scheme that can identify suitable idle MSs in good service zones as traffic agents TAs to relay traffic from those out-of-coverage MSs to the AP. The service coverage area of WLAN is then expanded. The QoS requirements . bandwidth of those MSs are considered in the selection process of corresponding TAs. Mathematical analysis verified by computer simulations shows that the proposed TA scheme can effectively reduce blocking probability when traffic load is light. Copyright 2006 Yang Yang et al. This is an open access article distributed under the Creative Commons Attribution License which permits .
