Performance Analysis of IEEE 802.11p for Continuous Backoff Freezing in IoV
Performance Analysis of IEEE 802.11p for Continuous Backoff Freezing in IoV
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DOI：
10.3390/electronics8121404
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发表时间：
2019-11
期刊：
影响因子：
2.9
通讯作者：
Qiong Wu;Siyang Xia;Q. Fan;Zhengquan Li
中科院分区：
文献类型：
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作者：
Qiong Wu;Siyang Xia;Q. Fan;Zhengquan Li
随着云计算和大数据的快速发展，传统的车辆自组织网络（VANHIOR）正在向车联网（IOV）演进。IEEE 802.11p协议作为车联网中的重要通信技术，得到了众多专家学者的研究。在IEEE 802.11p中，当检测到信道为忙碌时，节点的退避计数器将被冻结。然而，大多数研究在计算延迟时没有考虑连续回退冻结的可能性。因此，在本文中，我们专注于IEEE 802.11p连续回退冻结的性能分析。具体来说，我们建立了一个分析模型，分析在高速公路场景中，车辆可以通过车辆到基础设施（V2I）通信从路边的单位获得交通密度的广播性能。我们首先计算车辆密度和车辆数量之间的关系。然后，我们推导出车辆的数量和分组延迟之间的关系，根据马尔可夫链。其次，我们利用概率母函数（PGF）将传统的马尔可夫链变换到非饱和情况下的z域。最后，我们采用梅森公式推导出的数据包延迟。仿真结果表明，与不考虑连续回退冻结时的性能相比，该分析模型更为合理。
With the rapid development of cloud computing and big data, traditional Vehicular Ad hoc Networks (VANETs) are evolving into the Internet of Vehicles (IoV). As an important communication technology in IoV, IEEE 802.11p protocols have been studied by many experts and scholars. In IEEE 802.11p, a node’s backoff counter will be frozen when the channel is detected as busy. However, most studies did not consider the possibility of continuous backoff freezing when calculating delay. Thus, in this paper, we focus on the performance analysis of IEEE 802.11p for continuous backoff freezing. Specifically, we establish an analytical model to analyze the broadcast performance in the highway scene where vehicles can obtain traffic density from roadside units through Vehicle to Infrastructure (V2I) communications. We first calculate the relationship between vehicle density and the number of vehicles. Then, we derive the relationship between the number of vehicles and packet delay according to Markov chains. Next, we utilize the probability generating function (PGF) to transform traditional Markov chains into z domain under the situation of non-saturation. Finally, we employ the Mason formula to derive packet delay. As compared with the performance without considering the continuous backoff freezing, the simulation results have demonstrated that our analytical model is more reasonable.