Congestion control scheme for jointly regulating physical carrier sense range and minimum competition window in VANET

Abstract

Aiming at expandability of MAC layer broadcasting in a VANET with quick vehicle density change, the invention discloses a safe range carrier sense random back-off, SR-CSRB. Characteristics of Internet of Vehicles are considered, a physical carrier sense mechanism and an original back-off algorithm are improved, and the SR-CSRB is disclosed with the purpose of increasing beacon information broadcasting reception rate within a jump of neighbor node range. The SR-CSRB changes a traditional physical carrier sense mechanism, and the probabilities of simultaneous information transmission of neighbor nodes are reduced by introducing a concept of collision control; in addition, the broadcasting reception rate of the neighbor nodes is improved by utilizing the capture effect, and the simulation result also shows that the new channel access mechanism has superiority compared with traditional CSMA.

Description

technical field [0001] The invention belongs to the field of intelligent transportation, in particular to the field of information dissemination in intelligent transportation. Background technique [0002] Vehicle-to-vehicle communication is emerging as an important factor in future intelligent transportation systems, especially with regard to enhanced road safety. VANET will allow rapid distribution of safety messages, increasing drivers' awareness of traffic conditions beyond their line of sight. In Europe and the United States, the 5.9GHz spectrum has been allocated for vehicle communications. On the basis of IEEE 802.11 products, IEEE 802.11 task group p released a revised version in 2010. This version is a standard specially formulated for wireless access (WAVE) in the Internet of Vehicles environment. Although the IEEE 802.11p protocol takes into account the characteristics of VANET such as the relative speed between vehicles and the short duration of the connection,...

AI Technical Summary

Problems solved by technology

[0011] In the present invention, aiming at the low reception rate of beacon message broadcast on CCH in VANET, the packet loss rate due to hidden terminals and the packet loss rate due to simultaneous transmission of nodes in the safe range are obtained by modeling Relative to the size relationship, draw the conclusion that the simultaneous transmission of messages in the safe range is the main factor that causes packet loss, and propose a carrier sense random back-off mechanism in a safe range based on this conclusion, simulation shows that this proposed by the present invention The mechanism can significantly improve the broadcast reception rate of beacon messages in VANET

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