Abstract— In this paper, we propose a cross-layer partnerbased fast handoff mechanism based on HMIPv6, called as PHMIPv6 protocol. Our PHMIPv6 protocol is a cross-layer, layer-2 + layer-3, approach. A new node, called partner node, is adopted in PHMIPv6 protocol. A new layer-2 trigger scheme used in PHMIPv6 protocol is to accurately predict the next AP (access point) and then to invite a possible partner node in the area of the next AP. With the aid of the partner node, CoA can be pre-acquired and DAD operation can be pre-executed by the partner node before the mobile node initialize the handoff request. By the way, PHMIPv6 protocol can significantly reduce the handoff delay time and packet losses. In the mathematical analysis, we verify that our PHMIPv6 protocol offers a better handoff latency than MIPv6, HMIPv6, and SHMIPv6. Finally, the experimental results also illustrate that PHMIPv6 protocol actually achieves the performance improvements in the handoff delay time, and the pack...