在传感网和物联网的大力发展过程中,覆盖问题始终是该领域关注的核心问题.目前在诸多应用中,网络部署受各类影响因素的制约以及传感设备自身条件的限制,无法实现监测区域的完全覆盖.但如果借助某些特定的移动设备并按照有针对性的移动策略实施移动覆盖,就可以实现监测区域内的补全覆盖.基于此应用提出了一类新的覆盖问题——移动全覆盖问题,即在网络稀疏覆盖的环境下,利用移动节点的移动覆盖实现监测区域的全覆盖问题.针对该问题提出了分而治之的节点移动策略.首先,按照移动节点通信半径将整个监测区域划分成多个子区域;其次,以四叉树分层遍历的策略作为移动节点在子区域间的移动方案;最后,针对每个子区域内静态节点的覆盖状况制定相应的区域内的移动策略.实验结果表明采用本文提出的移动策略可以实现在移动节点移动较小距离的前提下达到整个区域的全覆盖,从而解决了稀疏网络环境下的全覆盖问题.
As the development of the WSNs and CPNs, coverage is always the core issue in practice. Due to the impact on environment of monitored region and the limitations inherent in sensors, the monitored region cannot be covered completely by the sensors in practical applications. In order to improve the coverage performance and make the monitored region full covered, diverse mobile equipments can be used to assist the sensors' coverage by their movement. So a new coverage issue is proposed in this paper, named mobile full-coverage, which indicates how to control the mobile sensors' movement to cover the whole regions under the sparse coverage circumstance. In this paper, an effective mobile strategy for the mobile full-coverage is presented. At first, the monitored region is divided into several sub-regions on the basis of the mobile devices' communication region. Secondly, the sub-regions are indicated by a quad-tree, and then the mobile nodes go through all sub-regions according to sequential traversal of the quad-tree. Finally, a related mobile strategy is designed in each sub-region based on the circumstance of covered regions. The experimental results show that the mobile strategy in this paper can achieve the full coverage in the monitored region with the minimum moved distance. Therefore, the strategy is an effective mobile scheme for the issue.