Handoff Trigger Nodes for Hybrid IEEE 802.11 WLAN/Cellular Networks††This work was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (NSERC). The authors may be contacted at todd@mcmaster.ca.

Future mobile handsets will often be multi-mode, containing both wireless LAN (WLAN) and cellular air in-terfaces. Vertical handoffs will commonly be used to pass voice calls to a cellular network when the user roams outside of WLAN radio coverage. Unfortunately, the transition from WLAN hotspot to cellular coverage is often very abrupt and leads to unacceptable call dropping rates. In this paper we propose andigoi investigate the use of …