tailieunhanh - Báo cáo hóa học: " Multiservice Vertical Handoff Decision Algorithms Fang Zhu and Janise McNair"

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: Multiservice Vertical Handoff Decision Algorithms Fang Zhu and Janise McNair | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 25861 Pages 1-13 DOI WCN 2006 25861 Multiservice Vertical Handoff Decision Algorithms Fang Zhu and Janise McNair Wireless Mobile Systems Laboratory Department of Electrical and Computer Engineering University of Florida . Box 116130 Gainesville FL 32611 UsA Received 8 October 2005 Revised 22 March 2006 Accepted 26 May 2006 Future wireless networks must be able to coordinate services within a diverse-network environment. One of the challenging problems for coordination is vertical handoff which is the decision for a mobile node to handoff between different types of networks. While traditional handoff is based on received signal strength comparisons vertical handoff must evaluate additional factors such as monetary cost offered services network conditions and user preferences. In this paper several optimizations are proposed for the execution of vertical handoff decision algorithms with the goal of maximizing the quality of service experienced by each user. First the concept of policy-based handoffs is discussed. Then a multiservice vertical handoff decision algorithm MUSE-VDA and cost function are introduced to judge target networks based on a variety of user- and network-valued metrics. Finally a performance analysis demonstrates that significant gains in the ability to satisfy user requests for multiple simultaneous services and a more efficient use of resources can be achieved from the MUSE-VDA optimizations. Copyright 2006 F. Zhu and J. McNair. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Future wireless networks must be able to coordinate services within a diverse network environment. For example a widely deployed third generation 3G cellular and data service .