中文摘要：

紧急交通信息,如碰撞预警、路口协作等,在车辆自组织网络（vehicular Ad Hoc network,VANET）中及时可靠地广播对安全驾驶至关重要.目前,现有工作对广播的研究主要解决VANET中多跳广播的连接问题.然而,在高动态的车辆环境下,通常需要直接的一跳广播来及时、可靠地传播紧急信息.针对路口2-D VANET中单跳广播的可靠性,给出3个衡量指标：数据分组接收率、距标记节点距离为d的范围内的数据分组接收率和数据分组投递率;推导了隐藏终端和并发广播问题下的3个指标的表达式;分析了侦听范围、干扰范围、数据分组大小、退避窗口大小和车辆节点密度对可靠性的影响.

英文摘要：

Reliability is an important issue for emergency message broadcast services in vehicular Ad Hoc network （VANET）. Most investigations of such broadcast in VANET focus on multi-hop connectivity, taking all one-hop links for granted. But potential emergency applications of broadcast in VANET include collision avoidance warning, intersection coordination, etc. Usually direct one-hop broadcast is demanded due to the stringent delay requirements in high mobility scenario. Three reliability metrics, which were the packet reception rate （PRR）, PRR with distance d from the sender （PRR（d）） and the node packet delivery probability （PDP）, were evaluated for one-hop broadcast at an intersection in 2-D VANET analytically. Expressions of these metrics were derived with consideration of the hidden terminal problem and collisions caused by concurrent transmissions. The impact of carrier sensing and interference ranges, the packet size, the back-off window size and the density of nodes on the reliability were investigated and discussed. Finally, some important observations to the broadcast at an intersection in 2-D VANET were provided, such as the PRR, PRR（d） and PDP were getting worse with the traffic density increase.