A neighbor caching mechanism for handoff in IEEE 802.11 wireless networks

Seamless handover in IEEE 802.11 for Quality of Service (QoS) demanding applications is one of the critical issues because of handover latency. In this paper, we propose the Neighbor Graph Cache (NGC) mechanism to reduce scanning latency while a mobile station tries to make a link-layer handover. The handoff latency can be greatly reduced through the NGC algorithm. We used OPNET modeler as the simulation tool. The simulation results show that the handover delay by NGC is 2.614 ms. It is less than 50 ms and able to meet the criteria of VoIP application.