Int’l J. of Business Data Communications and Networking, 3(3), 1-18, July-September 2007 1 Copyright © 2007, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. ABSTRACT This article introduces a distributed system, called wireless proxy, to mitigate the effects of user mobil- ity over streaming services on IEEE 802.11 wireless LANs (WLANs). It argues that a handoff procedure totally controlled by the client, depending on client mobility and configuration, can have negative effects over streaming services. In this way, mobile clients that remain associated with their current access point (AP) in poor channel conditions, severely affect the performance of streaming services. The presented distributed system monitors client mobility and induces mobile client handoffs when channel conditions worsen. Also, the system compensates streaming client and server underestimations of channel condi- tions. The obtained improvements using wireless proxy are experimentally tested using one of the most extended commercial streaming platforms and off-the-shelf WiFi devices. The main contribution of the developed system is that it works with unmodified IEEE 802.11 wireless NICs and APs, such as the ones widely deployed nowadays. Keywords: handoff; multimedia, user mobility; video streaming; wireless technologies INTRODUCTION One of the user access technologies that has achieved a greater commercial impact is that of wireless LAN (WLAN) based on IEEE 802.11 standards. In spite of the broad set of applications of this technology and the current support for user mobility, it still has some special charac- teristics which need to be considered. Wireless stations, prior to the transmission or reception of data, have to carry out several tasks: search for the best AP, perform an authentication and, then, associate with this AP. In a general situa- tion, the same process has to be repeated every time a client roams from the coverage area of Wireless Proxy: Distributed System to Mitigate the Effects of User Mobility Over Streaming Services on IEEE 802.11 Wireless LANs Manuel Vilas, University of Oviedo, Spain Xabiel G. Pañeda, University of Oviedo, Spain David Melendi, University of Oviedo, Spain Roberto García, University of Oviedo, Spain Victor García, University of Oviedo, Spain IGI PUBLISHING This paper appears in the publication, International Journal of Business Data Communications and Networking, Volume 3, Issue 3 edited by Jairo Gutierrez © 2007, IGI Global 701 E. Chocolate Avenue, Suite 200, Hershey PA 17033-1240, USA Tel: 717/533-8845; Fax 717/533-8661; URL-http://www.igi-pub.com ITJ3808