摘要
固有的高速移动节点和不可预测的环境使得车载自组织网络(Vehicular Ad-hoc Network,简称VANET)拓扑结构不断变化。为了确保有效的数据包传输,VANET中的节点应能适应VANET拓扑结构的变化。本文提出一种新的启发式和自适应模糊逻辑方案,根据网络和交通情况调整竞争窗尺寸和传输功率。现有的VANET方案只从一个参数优化竞争窗尺寸和传输功率,未考虑干扰这一主要因素在VANET劣化传输时的影响。在VANET中,由于干扰或在运行的时间内数据丢包可以出现在不同的传输阶段,在方案中,基于3个参数(即碰撞丢包率、信噪比和队列溢出),代表不同传输阶段的数据包丢包,模糊逻辑自适应地优化数据包竞争窗尺寸。传输功率通常是静态参数,在考虑了VANET干扰影响的情况下,也可以用启发式和自适应模糊逻辑方案优化。启发式和自适应模糊逻辑方案能评估道路交通仿真网络和城市交通网络仿真,其仿真结果表明,与默认的IEEE802.11P和现有的方案比较,此方案能提高吞吐量,降低端到端延迟和提高数据包传输成功率。
Rapid topology change in vehicular ad hoc network （ VANET ） is common due to the inherent high mobility nodes and unpredictable environments in VANET. To ensure efficient packet transmission, nodes in VANET should react adaptively to topology change in VANET. In this paper, we present a new heuristic and adaptive fuzzy logic scheme （ HaFL ） , which adapts the contention window size and transmission power according to netwnrk and traffic conditions. The current existing schemes in VANET utilize only a single parameter to optimize the contention window and transmission power without consideration on the effects of interference as one of the main factors in VANET transmission degradation. In VANET, packet loss can occur at different stages of transmission due to interference or due to elapsed time. In the proposed HaFL, fuzzy logic is used to adaptively optimize the contention window size based on three parameters namely collision rate, SINR and queue overflow which represent packet drop at different stages of transmission. Transmission power which is usually a static parameter is also optimized with consideration on the effects of VANET interference in the proposed HaFL. The performance of the proposed HaFL is evaluated in Vehicles in Network Simulation with road traffic simulator, Simulation of Urban mobility. Simulation results show that the proposed HaFL demonstrates adaptability with improved throughput, low end-to-end delay and higher packet success rate in comparison with the default IEEE802.1 lp and existing schemes.
作者
张宏
吕悦晶
ZHANG Hong LV Yue-jing(Transportation Institute, Inner Mongolia University, Hohhot 010021 School of Automotive and Traffic Engineering, Wuhan University of Science and Technology, Wuhan 430081, Chin)
出处
《汽车电器》
2017年第10期53-58,共6页
Auto Electric Parts
基金
内蒙古大学高层次人才引进项目(22200-5165118)
中央高校基本科研业务费资助项目(自然科学类)重点科研平台开放基金(310822171134)
关键词
VANET
竞争窗尺寸
传输功率
模糊逻辑优化
VANET
contention window size
transmission power
fuzzy logic optimization
