Abstract: In vehicle ad hoc network(VANET),vehicles need to switch from one road side unit(RSU) to another one frequently in urban traffic congestion,resulting in a long handoff delay of IPv6 mobility support protocol.A fast hand-over scheme based on proxy mobile router was proposed as a solution to the problem.The method that proxy mobile router’s switching in 3G/WiMAX communication domain triggers the handover of other vehicles in 802.11p communication domain was proposed to achieve the purpose of combining macro switch with micro switch.And then,this method can achieve the goal of mass fast switching.The analysis shows that this scheme is superior to other existing programs in switching efficiency and handoff delay.

Key words: VANET,IPv6 mobility,Proxy mobile router,Fast handover