Aiming at the features of wireless mobile communication, this paper proposes a new resource reservation scheme, Fast RSVP (resource reservation protocol), to guarantee the QoS of sessions for mobile IPv6. The scheme adopts cross-layer design, it cooperates two modules at different layers: Mobile IP module and RSVP module. By adding some primitives, the scheme lets the two modules work together to guarantee the QoS of sessions for mobile users. Fast RSVP imports a series of new mechanisms such as advanced resource reservation on neighbor tunnels, resource reservation on optimized routes, resource reservation for handover sessions, path merging etc. Simulation results show that Fast RSVP scheme, compared with other traditional RSVP extensions for mobile environments, has the following advantages: (1) it realizes a mobile node handover with QoS guarantees; (2) it avoids resource wasting caused by triangular routes and duplicate reservations in mobile IP handover process; (3) it distinguishes different types of reservation requests, greatly reducing the handover session forced termination rate while maintaining high performance of the network.