A method for improving the coverage of Internet of Vehicles safety information broadcasting

Abstract

The invention discloses a method for improving the coverage of safety information broadcasting in the Internet of Vehicles, which includes designing a non-uniform backoff window constraint sequence Xr and a method for dynamically adjusting the selection probability of the backoff window initial value of forwarding nodes at different distances from source nodes and the constraint sequence Xr The conditions to be met in the actual security information forwarding application scenario; according to the relative distance dr between the forwarding node and the source node, the distance constraint factor γr is calculated, and the constraint sequence Xr is constructed by γr; under the constraints of the constraint sequence Xr, each forwarding node generates its own The initial value of the back-off window, and then initialize the initial value of the back-off window counter to enter the back-off process to achieve access control to the shared medium. The present invention has the advantages of improving the effective coverage of multi-hop broadcasting of safety information in the CCH channel time slot by increasing the probability of forwarding data packets in a unit time slot by relatively distant nodes within one hop of the source node.

Description

technical field [0001] The invention relates to the technical field of Internet of Vehicles communication, in particular to a method for improving the broadcast coverage of safety information of the Internet of Vehicles. Background technique [0002] The Internet of Vehicles is the core part of the future intelligent transportation system (Intelligent Transportation System, referred to as ITS). Provide assisted driving, safety alarms, multimedia application services, etc., in order to reduce the rate of traffic accidents, implement emergency rescue, reduce traffic congestion, and improve traffic efficiency. According to the information carried by the Internet of Vehicles, its applications can be divided into two categories, namely: safety-related information and non-safety-related information. Among them, information related to security mainly uses the communication method of broadcasting. The broadcast communication method can be further divided into single-hop broadcast ...

AI Technical Summary

Problems solved by technology

[0004] For security information, in order to enable more nodes to receive security information in a short period of time, the broadcast process often uses multi-hop broadcasting, but the existing protocols have the following disadvantages: (1) The Internet of Vehicles communication protocol IEEE802 .11pMAC layer uses EDCA (Enhanced DistributedChannelAccess enhanced distributed channel access) mechanism, although this mechanism sets different priorities for different information types by distinguishing queues, but in the process of forwarding information with the same priority (such as Security information) channel competition is fair and disorderly. On the one hand, this disorder will inevitably lead to frequent collisions of information forwarded by adjacent nodes, so that security information cannot be effectively forwarded; on the other hand, from improving From the perspective of security information forwarding coverage, forwarding nodes at the edge of one-hop coverage of information source nodes have better forwarding coverage than their adjacent forwarding nodes, but in this disorderly competition mode, the two get channel usage The probability of information forwarding is the same, so it is not conducive to improving the effective coverage of security information

(2) In the application scenario of intelligent transportation, safety-related information has an effective time tolerance, and the maximum effective time tolerance of most safety-related information is 100ms, that is to say, the time and source of the safety information received by the receiving vehicle node The time interval for the node to send the information should be less than or equal to 100ms. If this time limit is exceeded, the data will be of no value to the vehicle node receiving the information. The control channel (CCH) time slot for safety information transmission has a duration of 50ms in each cycle, so the time available for safety information forwarding is very limited

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