Crossing ad hoc node assisted urban vehicle routing protocol method

The present invention provides a crossing ad hoc fixed node assisted routing protocol-SAGR (Static-Node Assisted Geographical Routing) method aiming at the traffic characteristic in the urban environment. Fixed nodes of a self-organization communication network are arranged at a crossing aiming at the characteristics of a VANET (Vehicular Ad Hoc Network) such as fast motion speed of a vehicle, easy occurrence of network splitting at the crossing and abundant vehicle auxiliary devices, etc. The fixed nodes are configured to calculate the SCORE value of each road connected with the fixed nodes through combination of the path distance, the vehicle density and the time delay and select the optimal routing path according to the SCORE value of each road. Besides, in a special road, an improved greedy algorithm is adopted to performing grouping and forwarding between vehicles. The SAGR protocol combines the selection strategy of a route and the motion characteristics of a vehicle, and the fixed node assistance and s