时效障碍物是一类由于传感器网络周围环境因素的改变所造成无线链路通信质量下降的障碍物。针对周期性时效障碍物对传感器网络所产生的影响提出了EasiTOD(EasiNet timeliness obstacledetection)检测调节机制,该机制利用时效障碍物对传感器网络链路产生周期性干扰的特点,将链路质量的周期划分为链路稳定时期与链路波动时期,并针对不同时期的链路状态采取相应的检测调节方法。通过实测验证,无线链路采用EasiTOD机制可以有效地检测并降低周期性时效障碍物对无线网络通信的干扰,同时在保证无线链路通信可靠性的前提下尽可能地降低网络能耗,从而提高传感器网络的整体性能。
The obstacles which affect the link quality of wireless sensor network can be divided into two categories by the time characteristics: one is the timeliness obstacles and permanent obstacles. The timeliness obstacles are a kind of barriers which are cause of the environment factors, and they reduce the wireless link quality. According to change in environment factors, the timeliness obstacles can be divided into peri obstacles and sudden obstacles. Considering the periodical impact on the wireless caused by the periodic timeliness obstacles, EasiTOD (EasiNet timeliness obs mechanism is proposed. Because the timeliness obstacles have a periodical impact on the wireless sensor network' link, EasiTOD divides the link period into two link states: stable period and fluctuant period. Based on previous two link states, EasiTOD adopts corresponding adjustment methods of detection. Experiments show that EasiTOD mechanism can detect timeliness obstacles of wireless sensor network. With the above mechanism, EasiTOD reduces the timeliness obstacles' interference on the communication of the wireless sensor network. EasiTOD also reduces energy consumption as much as possible on the basis of high communication reliability of network. Therefore, EasiTOD improves the overall performance of sensor networks.