Liu Yao, Zhou Hongjing, Huang Jiawei
School of Computer and Information Engineering, Hunan University of Technology and Business, Changsha 410205, China.
Key Laboratory of Hunan Province for Mobile Business Intelligence, Hunan University of Technology and Business, Changsha 410205, China.
Sensors (Basel). 2019 Jun 14;19(12):2691. doi: 10.3390/s19122691.
Cooperative communication is an effective method of improving the transmission performance for vehicular ad hoc networks. However, the rapid movement of vehicles leads to frequent changes in network topology and reduces the probability of successful data transmission on the medium access control (MAC) layer. In this paper, we propose an Optimal Cooperative Ad hoc MAC protocol (OCA-MAC) based on time division multiple access (TDMA). OCA-MAC utilizes multiple cooperative nodes to forward data, so as to improve the probability of successful data transmission. It chooses cooperative nodes according to direct successful transmission probability, communication range between potential helper node and destination node, and available time slot. Meanwhile, in order to avoid excessive transmission redundancy caused by multiple cooperative forwarding, the optimal number of cooperative forwarding nodes is obtained through analysis of a probabilistic model. Simulation results show that OCA-MAC improves the successful data transmission rate and reduces the number of transmission times and transmission delay compared to the multichannel TDMA MAC protocol (VeMAC) and the cooperative ad hoc MAC protocol (CAH-MAC).
协作通信是提高车载自组织网络传输性能的一种有效方法。然而，车辆的快速移动导致网络拓扑频繁变化，并降低了介质访问控制（MAC）层上数据成功传输的概率。在本文中，我们提出了一种基于时分多址（TDMA）的最优协作自组织MAC协议（OCA-MAC）。OCA-MAC利用多个协作节点来转发数据，从而提高数据成功传输的概率。它根据直接成功传输概率、潜在协助节点与目的节点之间的通信范围以及可用时隙来选择协作节点。同时，为了避免多次协作转发导致的过度传输冗余，通过对概率模型的分析得出协作转发节点的最优数量。仿真结果表明，与多信道TDMA MAC协议（VeMAC）和协作自组织MAC协议（CAH-MAC）相比，OCA-MAC提高了数据成功传输率，减少了传输次数和传输延迟。
