IAPP Modifications for a Location based Fast hand off Technique in wireles networks

802.11 standards have been defined by IEEE and are in continuous state of evolution and current research in this area is focused on providing data rates, QOS, security and interoperability equivalent to their wired counterparts. Provision of mobility in 802.11 based wireless networks is another big issue and algorithms providing low latency handoff with reduced data loss and signaling overhead needs to be developed. We have proposed a GPS assisted low latency handoff scheme for providing roaming in the 802.11 wireless networks. Currently available GPS devices are capable of providing location information with accuracy of up to few meters. We have suggested that all the mobile stations and access points are GPS enabled and handoff decision is based on GPS coordinates of the station (STA). This would further provide the possibilities of running other location based services. Use of inter access point protocol (IAPP) is mooted and we have proposed slight modifications in IAPP for exchange of GPS coordinates and channel information between the neighboring access points (AP). In our approach we have proposed to divide the AP range into two parts namely safe area and vulnerable area based on signal strength. Our handoff algorithm is triggered once mobile enters the vulnerable area and based on the current GPS position the STA obtains information about the neighboring AP where handoff is expected from the current AP. This algorithm reduces the scanning time to almost nil