In this paper, we focus on the cross layer design of the situation that AODV (ad hoc on demand distance vector) routing protocol is implemented in spatial-TDMA wireless networks. The routing discovery and routing maintenance strategy of AODV is simplified by utilizing the neighbor information kept by the spatial-TDMA protocol called USAP (unified slot assignment protocol). The new protocols reduce the communication overheads and consequently have a higher network throughput. We have verified this idea in the QualNet simulator. The simulation result shows that the routing overheads and the amount of route request messages sent by the nodes are reduced heavily. Meanwhile, it improves the network throughput performance.