Research On Broadcasting In Dense Wireless Sensor Network With Irregular And Dynamic Radio Coverage

The development of wireless sensor networks will greatly change our daily life. And, broadcasting is a widely used operation in a wireless sensor network. But simple flooding will cause broadcast storm problem, including redundant rebroadcasts, contention, and collision. It becomes more serious when broadcasting in densely deployed sensor networks. Many researches have been done to alleviate broadcast storm, but few of them have considered the impact of radio irregularity that results in the existence of asymmetry links between sensor nodes.In this paper, based on the Double-Covered Broadcast algorithm, we propose a new broadcast algorithm for dense wireless sensor network with irregular and dynamic radio coverage, called Sensor Double-Covered Broadcast (SDCB). Compared to DCB algorithm, SDCB's features are as follows.First, considering the existence of asymmetric links, we periodically update each node's asymmetric link neighbor set information and use it to dynamically select forward nodes during a broadcasting process.Second, considering that neighbor nodes right on the border of the radio coverage may not receive the broadcast packet correctly, we first select the forward nodes from the neighbor nodes whose received signal strength are above a certain threshold.Third, considering that nodes frequently selected as forwarders will become network bottleneck for consuming energy too fast, we give nodes with high-energy higher priority to be selected as forward nodes.In the end, we simulate SDCB on NS2 platform, comparing its effectiveness with DCB. The results show that SDCB has rather high broadcast delivery ration, lower broadcast forward ratio and low end-to-end delay.