Prediction-based routing method at intersection in vehicle self-organizing network

Abstract

The invention discloses a prediction-based routing method at an intersection in a vehicle self-organizing network, and mainly solves the problem that when a packet is routed at the intersection, a link is unstable in the prior art. The scheme for implementing the method is that: when the packet arrives at a previous hop node of the intersection, the node predicts the next intersection to which the packet is transmitted; a weight of each adjacent intersection is calculated according to the density of adjacent road sections and a distance from the next intersection to a destination, and the intersection with the largest weight is selected as the next temporary destination for transmitting the packet; and when the packet is forwarded in a greedy mode in the road section, if the selected nodeis positioned in the boundary of the transmission range and is opposite to a driving direction of the transmitting node, a node secondarily nearest to the destination is selected, otherwise the packet is directly forwarded to the selected node. Compared with the geographic routing in city scenarios (GPCR) protocol and the greedy perimeter stateless routing for wireless networks in urban vehicularscenarios (GpsrJ+ protocol), the method has the advantages that: the transmission rate of the packet is increased, the transmission time delay of the packet is reduced, and the method can be applicable to the vehicle self-organizing network.

Description

technical field [0001] The invention belongs to the field of communication technology, and mainly relates to a routing method in a vehicle self-organizing network VANET, which can be used for routing decisions at road intersections in urban scenes. Background technique [0002] An important application of VANET is to improve traffic efficiency and passenger travel convenience. These applications generally require long-distance data transmission. Due to the limitation of wireless transmission distance, multi-hop transmission is required. How to design an efficient routing protocol to successfully send data to the destination is an important research direction in the field of VANET. [0003] VANET has similar characteristics with mobile ad hoc network MANET. They are both self-organizing wireless networks without fixed infrastructure support and composed of scattered mobile nodes. Therefore, the routing protocol initially adopted by VANET is a mature routing protocol in MANET...

AI Technical Summary

Problems solved by technology

However, there are several problems as follows: ①The forwarding direction is only selected according to the one-hop neighbor nodes at the intersection, without considering the node density on the road section, and the packet may be forwarded to the road section with low vehicle density, causing the packet to fail to be transmitted, such as figure 2 As shown, node A carries a data packet destined for D, and the intersection node sends the packet to node B according to the information of its one-hop neighbor node, but the vehicle density of the road section where B is located is very low, which leads to network splitting and the grouping cannot continue Forward

②When selecting the next hop node, the driving direction of the vehicle is not considered. In this way, two vehicles with opposite driving directions will transmit data, which may cause a routing loop. At the same time, due to the high-speed driving of the vehicle, it is within the transmission range of the node at the time of selection The vehicle on the border, because it is the closest to the destination, will be selected as the next hop, but the node may have moved out of this range before the data transmission is completed

③The improved beacon will cause additional network overhead. According to the operation mode of the protocol, the two-hop neighbor information is only used when predicting the intersection. The beacons sent by all nodes carry the two-hop neighbor road section information, which will increase the network load. It is completely unnecessary for intersection nodes to send two-hop neighbor information

GyTAR and many other protocols that consider vehicle density believe that the greater the density, the better. This is reasonable from the perspective of routing alone, but considering the MAC layer, the greater the node density, the more sending nodes and packets. As a result, the node takes longer to access the channel, which will increase the transmission delay of the packet, instead of using the fast sending of the packet

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