Fast Handoff Implementation by Neighbor Graph with Help of Global Positioning System

IEEE 802.11b networks find unlimited applications. While roaming through an access points, a mobile node (MS) is frequently required to carry out a link layer handover. This mechanism causes a user intercept able connection loss and breaks in time-sensitive communication, especially when a network layer handover follows the link layer handover. In this paper, we propose a method to reduce handoff latency for IEEE 802.11b wireless networks with the help of Neighbor Graphs (NG), pre-scanning mechanisms and using a GPS based server which predetermines the next probable AP a mathematical techniques. IEEE 802.11 consist of11 channels among which the channels 1, 6 and 11 do not mutually overlap. The non overlapping channels are expected to have a lower carrier-to-interference (CI) ratio as compared to the other channels in attendance to the same base station, which increases the channel‟s accessibility during handoff. Based on the NG pre-scanning mechanism and next AP prediction using the GPS, when handoff criterions have been met, we design an algorithm to first scan the channels 1, 6 and 11, if present under the next Access Point (AP), to reduce the scanning delay. We also introduce pre-authentication mechanism, which will effectively reduce the message processing delay.