Traffic safety management (TSM) information multihop broadcasting method

Abstract

The invention discloses a traffic safety management (TSM) information multihop broadcasting method. The method comprises the following steps of: detecting a traffic safety event vehicle to serve as a source node to broadcast TSM information; calculating a reference waiting time slot Tn of a highway section in which a node is positioned by the node which receives the TSM information according to a weight factor, namely the distance between the node and the source node, dynamically regulating additional forwarding waiting time Delta n according to an estimated value of link quality signal to interference plus noise ratio (SINR), and calculating and acquiring waiting time tn of the node for transmitting a message; and when the waiting time tn is reduced to zero, immediately broadcasting request traffic forward (RTF), after a previous forwarding node receives the RTF, determining a single relay node to transmit a data packet, and immediately forwarding the received TSM information after the node receives the RTF. By the method, link quality information is combined, data forwarding reliability is fully guaranteed, the phenomenon of forwarding collision between multiple nodes in the same highway section is reduced at the same time, and the link load and data redundancy in a media access control (MAC) layer are effectively reduced based on an RTF / authorized traffic forward (ATF) forwarding confirmation mechanism.

Description

technical field [0001] The invention relates to the technical field of network communication, in particular to a method for multi-hop broadcasting of traffic safety information. Background technique [0002] At present, the Vehicular Ad-Hoc Network (VANET) system is the basic information bearing platform of the intelligent transportation system. (Road Side Unit, RSU) information interaction can provide a safer, faster and more comfortable driving environment for people to travel. VANET has good application prospects in collision warning, assisted driving, road traffic information query, multimedia entertainment and Internet information services, etc., especially in the application of anti-collision warning has received extensive attention. It has the incomparable advantages of traditional electronic anti-collision systems. Through the wireless communication technology between vehicles, traffic safety information such as emergency warnings can be quickly distributed to surro...

AI Technical Summary

Problems solved by technology

However, since the waiting time of all nodes in the same road section is the same, in the state of dense traffic flow, this algorithm will lead to serious competition problems among multiple nodes in the same road section, so an algorithm based on time slot p persistence is proposed To further reduce the probability of collision

However, due to the similar distance between nodes on the same road segment, the difference in forwarding probability p is small, and it cannot be guaranteed that there is a unique forwarding node at the same time. The remote node forwards preferentially, which increases the transmission delay of emergency messages in VANET. Therefore, there are obvious defects in the scheme of suppressing broadcast storm based on random probability

[0005] The core idea of ​​the broadcast algorithm in the above-mentioned prior art is to preferentially select the farthest node within a hop range for forwarding. Although this can reduce the number of forwarding hops and transmission delay to a certain extent, due to multipath fading, shadow effect, the Doppler effect of high-speed mobile nodes and the occlusion of buildings have seriously affected the quality of wireless channels. In addition, VANET uses open frequency bands, which makes the bit error rate of wireless network information high, and it is difficult to guarantee the broadcast of traffic safety information. transmission reliability

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