车载自组网中最远转发机制的可靠性改进

Improving the reliability of the most forward mechanism within radius scheme in VANETs

车载自组网是传统的移动自组织网络在交通道路上的应用。在车载自组网中,最远转发机制[1]能够有效降低数据传播跳数,减少冗余发送,但最远转发机制的可靠性将因最远节点失效而受到影响。在分析和实验验证节点高速运动将导致严重的最远节点失效问题的基础上,提出了两种对最远转发机制进行改进的方法:安全距离法和失效预测法。安全距离法选择最接近计算出的安全距离的邻居作为转发节点;失效预测法通过邻居的状态参数对其位置进行预测,进而避免选择那些可能已经脱离通信半径的邻居作为转发节点。多个仿真实验表明,两种改进方法都能不同程度地降低转发节点失效的比例,提高消息传播的可靠性。

VANETs is an application of traditional mobile ad hoc networks in traffic roads. In VANETs, most forward within radius scheme can effectively reduce hops of data dissemination and re- dundancy sending, however, its reliability can be adversely affected due to the farthest node failure. Given that the high mobility of VANETs may cause serious farthest node failure, which is analyzed and verified by experiments, we propose two improved methods, i.e. the safe distance method and the fail- ure prediction method. The safe distance method chooses the neighbors whose distance are closest to the calculated safe distance as relay nodes, while the failure prediction method estimates neighbors＇ position by state parameters, therefore avoiding choosing those neighbors who may be out of communication ran- ges as relay nodes. Simulation results show that the two methods can reduce the failure rate of relay nodes and improve the reliability of data dissemination to certain extent.