Greedy geographic routing protocol hello packet exchange method

Abstract

The invention discloses a greedy geographical routing protocol Hello message exchange method. The realization scheme is as follows: firstly, the width of the road is considered to be much smaller than the communication radius of the vehicle, and the vehicles on the road can be regarded as a one-dimensional network approximately. The communication range of the nodes is discretized, and the link state is mathematically modeled using the Markov process, which is described as a Markov chain with absorbing boundaries, and then the link connectivity probability is calculated according to the first-arrival probability and one-step transition probability matrix. According to the statistical characteristics, the link connection probability and the beacon exchange period can establish a corresponding relationship. The width of the link disconnection interval of the vehicle at the minimum hello message exchange period is designed, and the neighbor nodes in the link disconnection interval will be deleted by the forwarding node. Compared with the greedy geographical routing protocol, this method can improve the success rate of data packet transmission and obtain a small control overhead, which can be used in VANET.

Description

technical field [0001] The invention belongs to the technical field of communication, and mainly relates to a hello message exchange method of a greedy geographic routing protocol in a vehicle ad hoc network. Background technique [0002] In the VANET, the greedy geographical routing protocol calculates the distance to the target node based on the location information of the surrounding one-hop neighbor nodes and performs greedy forwarding. Each node needs to establish and maintain the neighbor node table through the Hello message exchange, so as to obtain the local topology status information. However, most greedy geographic routing protocols use periodic Hello message exchange, that is, each node broadcasts a Hello message with a lifetime of 1 hop to all neighbor nodes to inform itself of its existence and location information. To build and maintain their own neighbor node table. In the traffic environment, due to the roads in the VANET restricting the trajectory of vehi...

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Problems solved by technology

In the traffic environment, due to the roads in the VANET restricting the trajectory of vehicles, the existence of roadside obstacles, non-uniform vehicle distribution and high-speed movement of vehicles, there is poor link stability, and it is easy to In the periodic Hello message exchange algorithm, the location information of the neighbor nodes maintained by the node cannot accurately reflect the change of the node location, nor can it reflect the on-off of the link in time, so that the best next The jump node will become a non-optimal candidate node, and the robustness and immediacy of data transmission will be seriously disturbed

[0003] The existing Hello message exchange algorithm is implemented in the Ad hoc network. The VANET is a highly dynamic network. There is a speed difference between vehicles. The width of the lane is relatively small compared to the communication radius of the vehicle. The vehicles can be considered to exist in a In the three-dimensional space, the connectivity analysis of the Ad Hoc network cannot be directly introduced into the VANET; on the other hand, most of the hello message exchange cycles formulated by these algorithms are obtained qualitatively, lacking the knowledge of the network dynamic characteristics and link characteristics. theoretical analysis

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