Vehicle network-accessing method based on IEEE 802.11p

Abstract

The invention discloses a vehicle network-accessing method based on IEEE 802.11p. The method can adapt to the requirements of vehicular ad-hoc network safety applications for time delay and acceptance rates. The VeDA which is based on 802.11p / DSRC allows vehicles to access to a shared channel in a contention-free period. The VeDA scheme supports two safety services (emergency safety messages and route safety messages) with different priorities and provides a strict time delay limit. The VeDA makes a DTIM frame divided into a contention-free period and a contention period. Two types of safety messages are accessed to the channel through VeDA Opportunities in a predetermined way. VDAOPs are multiple time slots of the contention-free period. The non-safety messages are accessed to the channel in the contention period in a contention means. As proved by simulation effects, the VeDA can effectively guarantee the time delay and the acceptance rate of safety messages. Especially in high communication load conditions, the VeDA is better than an accessing scheme based on a back-off algorithm in terms of time delay and acceptance rates.

Description

technical field [0001] The invention relates to a channel access method in a vehicle self-organizing network, and belongs to the technical field of network communication. Background technique [0002] Vehicular Ad-hoc Network (VANET for short). VANET is an ad hoc network dedicated to vehicle communication and is an important part of the intelligent transportation system. The Federal Communications Commission uses the 75Mhz frequency band of 5.850-5.925GHz exclusively for intelligent transportation systems. Through dedicated short-range communication (DSRC), this 75Mhz is specially used for communication between vehicles (Vehicle-to-Vehicle, V2V) and vehicles (Vehicle-to-Infrastructure, V2I), so this 75Mhz is also used It is called a DSRC channel. The IEEE working group specially established the IEEE 802.11p group to conduct research on DSRC and proposed the WAVE mode. [0003] The DSRC channel consists of seven 10MHz channels. In addition, a total of 5MHz spectrum from ...

AI Technical Summary

Problems solved by technology

There are some problems in these two improvements: (1) Most of all, changing the competition window adjustment mechanism does not need to estimate the number of nodes in the network, but because the parameters are fixed, the performance is often not optimal

(2) Although the method of setting the most parameters can achieve the optimum, it needs to estimate the number of competing nodes online, so the estimation error has a great influence on the network performance

However, due to the complexity of the network conditions, the static parameter settings in EDCA cannot optimize the system performance. Many studies have shown that the performance of EDCA is not satisfactory due to the high collision rate in the network under high load conditions. , and in the case of low load, it will cause waste of idle time slots

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