Handoff in Hybrid Wireless Networks based on Self Organization

Future mobile handsets will often be multi-mode and may include both wireless LAN (WLAN) and cellular air interfaces. When this type of handset roams in and out of WLAN coverage, connections must be transferred to the new network point of attachment. In order to support real-time wireless services, seamless vertical handoff is an essential requirement. In this paper we propose the use of ad hoc relaying during vertical handoff in hybrid WLAN/Cellular systems. The proposed method improves handoff algorithm behavior in terms of handoff dropping probability and other mobility performance measures. Both analytic models and simulation results support the effectiveness of the proposed method.