VANET中一种安全消息拥塞控制机制

Congestion control mechanism in VANET for safety messaging

针对车辆无线自组织网络在车流量密度大的情况下,周期性安全消息产生的Beacons可能占据整个信道带宽,从而导致信道拥塞的问题,提出了一种基于调整Beacon频率和车辆通信半径的拥塞控制机制。该机制首先为周期性安全消息和突发事件安全消息提出了一个信道分配算法,将周期性安全消息在信道中占用的带宽资源限定在一定的门限以下,保证有足够的信道资源传输突发事件安全消息。然后,在保证车辆用户安全的条件下,根据精确性要求和成功接收率,动态地调整Beacon频率和车辆通信半径,来控制信道中能够容纳的用户数,避免信道拥塞。

In vehicular ad-hoc network （VANET）, periodic safety messages （beacons） may consume the entire channel bandwidth in dense traffic, resulting in a saturated/congested channel. As a solution to the problem, a congestion control mechanism based on beacon frequency and communication radius adjusting was proposed. Firstly, a basic channel resource allocation algorithm for periodic safety message （PSM） and event-driven safety message （EDSM） was proposed, which limits the beacon toad level below a specific threshold and thus implicitly reserves enough bandwidth for EDSM. And then, according to the accuracy and probability of successful reception, the beacon frequency and communication radius dynamically was adjusted to control the number of vehicles in the channel, while maintaining the vehicular safety.