Extending lifetime of sensor network by introducing mobile nodes and its evaluation using real devices

在这项研究中，我们提出了一种最大化无线传感器网络寿命的方法，通过使最少的节点工作并让其他节点休眠来实现k-覆盖目标区域的无线传感器网络的寿命。为此，我们首先建立了在每个时刻确定每个传感器节点的工作模式和多跳通信路径以最大化k-覆盖时间的问题。该问题是一个典型的组合优化问题，很难在实际时间内找到最优解。因此，我们提出了一种对每个较短时间段进行周期性求解的方法，该方法通过对整个时间段进行细分来实现。我们提出了两种方法，一种是根据活跃节点对域k覆盖的贡献度大小选择活跃节点，另一种是找出覆盖域为1的层，选择k个活跃层进行k覆盖。第二种方法被认为具有更强的容错性。为了评估我们的算法在k覆盖时间方面的有效性，我们将我们的方法与其中一些建议的特征被禁用的方法进行了比较。通过基于仿真的比较，我们证实无论k和节点数如何，所提出的方法都比其他方法获得了1.1到1.7倍的生命周期。

In this study, we proposed a method for maximizing the lifetime of a wireless sensor network which k-covers the target field, by making minimum number of nodes operate and putting other nodes in sleep. For this objective, we first formulated the problem to decide the operating mode for each sensor node and the multi-hop communication route at each time to maximize the k-coverage time. This problem is a typical combinatorial optimization problem, and thus it is hard to find the optimal solution for practical time. So, we proposed a method which periodically finds the solution for each of shorter time periods, which are made by subdividing the entire time period. We proposed two methods; the first one is to choose active nodes in order of their contribution degree to the field k-coverage, and the second one is to find layers that each of them 1-covers the field, and choose k active layers for k-coverage. The second method is considered to be more fault-tolerant. In order to evaluate the effectiveness of our algorithms in terms of k-coverage time, we compared our methods with methods in which some of the proposed features are disabled. Through simulation-based comparison, we confirmed that the proposed methods achieve 1.1 to 1.7 times longer lifetime regardless of k and the number of nodes, than the other methods.