The handoff algorithms in the current generation of 802.11 networks are primarily reactive in nature, because they wait until the link quality degrades substantially to trigger a handoff. They further rely on instantaneous signal strength measurements when choosing the best AP. This approach leads to handoff delays on the order of 1-2 seconds that are unacceptable for delay sensitive applications such as VoIP. We propose a fundamentally new approach to handoffs that is based on continuous monitoring of wireless links. In our approach, a client measures the beacon strengths of all the APs operating on the current, and the overlapping channels, and makes its handoff decisions based on the long-term, and short-term trends in these signals. We show through experiments in a campus wireless network that our proposed algorithms result in more than 50% reduction in average handoff delays, while having the potential to improve overall user performance. Our algorithms have been implemented in t...