Vehicular Ad hoc network routing method based on autonomously acquired road information

Abstract

The invention discloses a vehicular Ad hoc network routing method based on autonomously acquired road information. The method is characterized in that when a packet forwarding direction and a vehicle driving direction are different, on the basis of the valid time of links and the distance from a predicted position of a vehicle to a target intersection, forwarding priority values of nodes are calculated, and therefore the valid time of packet transmission lines is long, and the stability of the links is improved during a routing process, and moreover, a node forwarding packet near a destination node is selected by combining the directions, and therefore the transmission time of the packet and the condition that the packet is transmitted repeatedly on the same road segment are reduced, and the time delay of packet transmission is greatly reduced. According to the method disclosed by the invention, road density information can be acquired more accurately, and moreover, routing nodes which are more efficient are selected by utilizing real-time road information more effectively. As a piecewise autonomous road density estimation method and a packet forwarding scheme of integrating a direction parameter and a position parameter are adopted by the method, the goal that the vehicle autonomously acquires the real-time road density information is achieved.

Description

technical field [0001] The invention relates to the technical field of network routing, in particular to a vehicle-mounted ad hoc network routing method based on autonomous acquisition of road information. Background technique [0002] At present, the vehicle communication network is a research topic that has attracted much attention. The development of wireless communication networks, the demand for safe driving, and the attention of automobile manufacturers and public transportation management agencies have prompted Intelligent Transportation System (ITS, Intelligent Transportation System) and vehicle ad hoc networks. (Vehicular Ad Hoc Networks, VANET) concept formation. Due to the frequent changes of VANET network topology, the movement of nodes in urban environment is limited by the road layout and the obstruction of wireless signals by roadside obstacles makes the design of its routing protocol more complicated than that of mobile ad hoc networks. Therefore, how to comb...

AI Technical Summary

Problems solved by technology

[0010] The road density estimation method used is the road density calculated by the sum of the vehicles encountered by the vehicle on the road and the total length of the road. This is a statistical average, which does not take into account the random distribution of vehicles in urban roads. and inhomogeneity, so that there is a large error between the estimated road density and the actual road density, which reduces the stability of the routing path

Moreover, since the vehicle wants to broadcast the vehicle density information of the road it is estimated by itself, and obtain the density information of other roads at the same time, it needs to periodically broadcast beacon messages. When the number of nodes increases, a large number of beacons Messages will cause network congestion, and conflicts will occur when channels are used based on the competition mechanism, resulting in a large transmission delay

In addition, if there are multi-hop breakpoints on the road with sparse nodes, the road density information cannot be propagated, which will cause errors in the estimation of road density, which may lead to routing errors and reduce the efficiency of packet transmission.

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