In multihop cellular network environments, the mobility is a major factor that disturbs finding a reliable routing path between mobile node (MN) and access node (AN). In order to minimize the effect of mobility, we propose fast route discovery protocols, which decrease the variation of link costs during the route discovery period and so achieve the reliable route setup. The proposed schemes use inhibit access control, priority access control, or hybrid control for the fast and reliable route discovery in view of cross-layer design. Simulation results show that the proposed route discovery protocols can decrease route discovery time and increase total received power compared with the conventional scheme.