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Design and Implementation of Geographical Handoff System Using GPS Information  

Han, Seung-Ho (부산대학교 컴퓨터공학과 이동통신연구실)
Yang, Seung-Chur (부산대학교 컴퓨터공학과 이동통신연구실)
Kim, Jong-Deok (부산대학교 컴퓨터공학과 이동통신연구실)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.35, no.1A, 2010 , pp. 33-43 More about this Journal
Abstract
Recently, users want to use real-time multimedia services, such as internet, VoIP, etc., using their IEEE 802.11 wireless lan mobile stations. In order to provide such services, a handoff among access points is essential to support the mobility of a node, in such an wide area. However, the legacy handoff methods of IEEE 802.11 technology are easy to lose connections. Also, the recognition of a disconnection and channel re-searching time make the major delay of the next AP to connect. In addition, because IEEE 802.11 decides the selection of an AP depending only on received signal strength, regardless of a node direction, position, etc., it cannot guarantee a stable bandwidth for communication. Therefore, in order to provide a real-time multimedia service, a node must reduce the disconnection time and needs an appropriate algorithm to support a sufficient communication bandwidth. In this paper, we suggest an algorithm which predicts a handoff point of a moving node by using GPS location information, and guarantees a high transmission bandwidth according to the signal strength and the distance. We implemented the suggested algorithm, and confirmed the superiority of our algorithm by reducing around 3.7ms of the layer-2 disconnection time, and guaranteed 24.8% of the communication bandwidth.
Keywords
Predict Handoff; Geographical Handoff; IEEE 802.11 WLAN; Passive Scan; RSSI; GPS;
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  • Reference
1 V. Brik, V. Mishra, and S. Banerjee, "Eliminating Handoff Latencies in 802.11 WLANs using Multiple Radios: Applications, Experience, and Evaluation," ACM Internet Measurement Conference 2005, October 2005.
2 IEEE 802.11, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE 802.11-2007.
3 ITU-T Recommendation G.114: One-Way Transmission Time, February 1996
4 Madwifi [online] http://www.madwifi-project.org
5 SL Tsao, and YL Cheng, "Improving Channel Scanning Procedures for WLAN Handoffs," Vol. 4809 Lecture Notes in Computer Science, 2007.
6 S Mellimi, SV Rao, "Location Based fast MAC Handoffs in 802.11," Wireless, Mobile and Multimedia Network, 2008.
7 H. Kim, S. Park, C. Park, J. Kim, and S. Ko, "Selective Channel Scanning for Fast Handoff in Wireless LAN using Neighbor Graph," ITC-CSCC 2004, July 2004.
8 W Wanalertlak, B Lee, "Global Path-Cache Technique for Fast Handoffs in WLANs," ICCCN 2007.
9 AirMagnet, WiFi Analzer Tool [online] http://www.airmagnet.com
10 H Wu, K Tan, Y Zhang, Q Zhang, "Proactive Scan: Fast Handoff With Smart Triggers for 802.11 Wireless LAN," IEEE INFOCOM 2007.
11 H.S Park, S.H Han and J.D Kim, "Vehicular Client Roaming and Location-based Handoff Through Multiple WLAN APs in a Container Terminal," ICHIT2009, August 2009.
12 TY Wu, CC Lai, HC Chao, "Efficient IEEE 802.11 handoff based on a novel geographical fingerprint scheme," Wireless Communications and Mobile Computing, 2006.
13 A Dutta, S Madhani, W Chen, "GPS Assisted fast-handoff mechanism for real-time communication," 2006 IEEE Sarnoff Symposium, 2006.
14 Free space loss at 2.45Ghz [online] http://huizen.deds.nl/~pa0hoo/helix_wifi/linkbu dgetcalc/wlan_budgetcalc.html
15 Iperf, UDP Bandwidth Tool [online] http://sourceforge.net/projects/iperf
16 J. Montavont and T. Noel, "IEEE 802.11 Handovers Assisted by GPS Information," Proceedings of the 2nd IEEE International Conference on Wireless and Mobile Computing, Networking and Communications, June 2006.
17 A. Mishra, M. Shin, and W. Arbaugh, "An Empirical Analysis of the IEEE 802.11 MAC Layer Handoff Process," ACM Mobile Computing and communications Reviesw33, April 2003.