This study develops a novel IEEE 802.21 MIH (Media Independent Handover) mechanism for next generation vehicular multimedia network. An adaptive QoS management mechanism is also proposed. By obtaining received signal strength parameters, the proposed Mm framework can determine the best available network. The adaptive QoS mechanism substantially improves the performance of real-time multimedia applications. The simulation results show that average handover time is slower than both UMTS and WiMAX when the MIH mechanism is used in vehicular network. However, the simulation results confirm that using the IEEE 802.21 MIH mechanism can increase overall throughput. Increased throughput is satisfactory compensation for increased handover time.