An OFDMA-Based MAC Protocol for Next-Generation VANETs
An OFDMA-Based MAC Protocol for Next-Generation VANETs
复制标题
DOI：
10.1109/tvt.2014.2361392
复制
发表时间：
2015-09-01
影响因子：
6.8
通讯作者：
Masini, Barbara Mavi
中科院分区：
文献类型：
--
作者：
Bazzi, Alessandro;Zanella, Alberto;Masini, Barbara Mavi
车辆自组织网络（vanet）可实现更高的安全性、增强的移动性管理和新的信息娱乐服务。目前，预计在VANETs的介质访问控制（MAC）层的标准是IEEE 802.11p，它是基于载波感知多址与避免碰撞（CSMA/CA）。然而，在繁忙的交通条件下，CSMA/CA存在较高的碰撞概率，特别是在隐藏终端存在的情况下。此外，当需要高数据速率时，采用请求-发送/清除-发送（RTS/CTS）机制并不有效。如果要处理高吞吐量的业务，就应该设计一个新的MAC协议。为此，本文提出了一种新的基于正交频分多址（OFDMA）的vanet MAC协议（OBV），并将其与其他MAC协议进行了比较。为了验证所提出的算法的可行性和性能，我们首先提出了一个简化场景下的分析模型。然后，我们在现实场景中开发详尽的模拟，考虑到城市和高速公路环境。结果表明，OBV优于所有参考协议，在重载网络条件下，其吞吐量甚至翻了一番。
Vehicular ad hoc networks (VANETs) enable higher safety, enhanced mobility management, and new infotainment services. Currently, the foreseen standard at the medium access control (MAC) layer for VANETs is IEEE 802.11p, which is based on carrier sense multiple access with collision avoidance (CSMA/CA). However, under heavy traffic conditions, CSMA/CA suffers from a high collision probability, particularly in the presence of hidden terminals. Furthermore, the adoption of the request-to-send/clear-to-send (RTS/CTS) mechanism is not effective when a high data rate is required. If high-throughput services are addressed, a new MAC protocol should, thus, be designed. To this aim, in this paper, we propose a new protocol, which is denoted as the orthogonal frequency-division multiple-access (OFDMA)-based MAC protocol for VANETs (OBV), and we compare it with other MAC protocols taken as benchmarks. To verify the feasibility and the performance of the proposed algorithm, we first propose an analytical model in a simplified scenario. Then, we develop exhaustive simulations in realistic scenarios, considering both urban and highway environments. Results show that OBV outperforms all reference protocols, even doubling their throughput under heavy-load network conditions.